Methods and systems for controller-based network topology identification, simulation and load testing

ABSTRACT

A method includes receiving information describing an addition of a first site comprising at least one application to an existing network wherein the information is selected from the group consisting of type of site, planned connectivity to the site and planned policies for the site and estimating an impact on the operation of the at least one application and associated network traffic using statistical analysis of monitored data collected from a second site similar to the first site.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication Ser. No. 62/051,293 filed Sep. 16, 2014, which is herebyincorporated by reference in its entirety.

BACKGROUND

The enterprise information technology (IT) operating model has shiftedfrom a model wherein an enterprise may own, maintain, and operate the ITinfrastructure necessary for the enterprise, to a model wherein theenterprise may also work with third parties who may provide enterpriseIT services to the enterprise. As a result, management of the enterpriseIT operating model has become more complex, as enterprises may now usepublic cloud infrastructure, software-as-a-service (SaaS)infrastructure, and private or virtualized data center infrastructure128, and the like. While the infrastructure may be changing, the varietyof applications used within the enterprise is also increasingsignificantly, further complicating the management and maintenance ofthe infrastructure, and requiring greater bandwidth to support theperformance that enterprise users 168 of these applications have come toexpect. Therefore, what is needed are methods and systems for flexiblydefined communication network controller-based control, operations, andmanagement of networks using a multi-tenant controller 122. Givenincreasing complexity in connecting users 168, devices, andapplications, a flexible approach to define, control and operate anetwork without worrying about the underlying virtual private network(VPN) protocols and configuration, routing protocols, link types, linkavailability and quality of service (QoS). Such methods and systems mayautomatically monitor and control the network, allowing transitioningfrom legacy networks for IT to a flexibly defined communication networkcontroller based control, operations, and management of networks.

SUMMARY

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a network requirement for at least oneapplication, dynamically determining a link suitable for datatransmission in accordance with a policy based at least in part on acurrent network condition to meet the network requirement and routingone or more application network data flows associated with the at leastone application over the link.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a network requirement for at least oneapplication, determining a link suitable to meet the network requirementbased, at least in part, on at least one of a plurality of applicationidentification details and an application traffic profile and routingone or more application network data flows associated with the at leastone application over the link.

Any of the embodiments described above wherein the application isoperating at a node.

Any of the embodiments described above wherein the application isoperating at a branch.

Any of the embodiments described above wherein dynamically determiningthe link is performed by a configurable spoke device.

Any of the embodiments described above wherein the configurable spokedevice maintains path configuration information.

Any of the embodiments described above wherein path configurationinformation is selected from the group consisting of bandwidthavailability on a link, a latency profile and a traffic volume cap.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a signature for each of a plurality ofapplications based, at least in part, on at least one of a domain name,a URL, a Server Network Identity (SNI), source IP address, a destinationIP address, a source port, a destination port, any sequence of bytes inone of a static position and a dynamic position in encrypted orunencrypted flow transactions, any sequence of bytes following amatching previous sequence of bytes in encrypted or unencrypted flowtransactions, at least one of a size, a transmission and a frequencypattern of encrypted flow transactions, an order and a pattern of flowestablishment and data relative to other flows seen and HTTP metadata,transmitting each of the signatures to a branch device and transmittinga policy string defining a business policy to be applied to a data flowexhibiting the signature to the branch device.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving a signature for each of a plurality of applicationsbased, at least in part, on at least one of a domain name, a URL, aServer Network Identity (SNI), source IP address, a destination IPaddress, a source port, a destination port, any sequence of bytes at oneof a static position and a dynamic position in encrypted or unencryptedflow transactions, any sequence of bytes following a matching previoussequence of bytes in encrypted or unencrypted flow transactions, atleast one of a size, a transmission and a frequency pattern of encryptedflow transactions, an order and a pattern of flow establishment and datarelative to other flows seen and HTTP metadata, receiving at least onepolicy string defining a business policy, analyzing at least one networkdata flow to detect the presence of the signature and applying thebusiness policy to the at least one network data flow comprising thedetected signature.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to determine a signature for each of a plurality ofapplications based, at least in part, on at least one of a domain name,a URL, a Server Network Identity (SNI), source IP address, a destinationIP address, a source port, a destination port, any sequence of bytes atone of a static position and a dynamic position in encrypted orunencrypted flow transactions, any sequence of bytes following amatching previous sequence of bytes in encrypted or unencrypted flowtransactions, at least one of a size, a transmission and a frequencypattern of encrypted flow transactions, an order and a pattern of flowestablishment and data relative to other flows seen and HTTP metadata,transmit each of the signatures to a branch device and transmit a policystring defining a business policy to be applied to a data flowexhibiting the signature to the branch device.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device is configured to receive a signature for each of aplurality of applications based, at least in part, on at least one of adomain name, a URL, a Server Network Identity (SNI), source IP address,a destination IP address, a source port, a destination port, anysequence of bytes at one of a static position and a dynamic position inencrypted or unencrypted flow transactions, any sequence of bytesfollowing a matching previous sequence of bytes in encrypted orunencrypted flow transactions, at least one of a size, a transmissionand a frequency pattern of encrypted flow transactions, an order and apattern of flow establishment and data relative to other flows seen andHTTP metadata, receive at least one policy string defining a businesspolicy, analyze at least one network data flow to detect the presence ofthe signature and apply the business policy to the at least one networkdata flow comprising the detected signature.

Any of the embodiments described above wherein the policy stringcomprises elements are selected from the group consisting of a useridentity, a SERVICE, a path and a VXWAN.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises checking at a predetermined interval a status of one or morenetwork paths to a remotely located application, rating the relativestatus of each of the one or more network paths wherein the rating isbased at least in part on at least one of network latency and anapplication level transaction latency and utilizing the rating to routean application data flow associated with the application.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device is configured to check at a predetermined interval astatus of one or more network paths to a remotely located application,rate the relative status of each of the one or more network pathswherein the rating is based at least in part on at least one of networklatency and an application level transaction latency and utilize therating to route an application data flow associated with theapplication.

Any of the embodiments described above wherein the rating of the networkpaths is in the context of an operability of an application.

Any of the embodiments described above wherein the rating of the networkpaths is further based, at least in part, on a bandwidth of the path, aMOS score, a packet loss and jitter.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a delivery location of an application based, atleast in part, upon at least one of manual information collection,triangulation based on source DNS queries and application probing,analyzing at least one network traffic flow associated with theapplication to extract data comprising at least one of a user location,a closest application delivery location and a source of user flowservice, aggregating the extracted data to identify a plurality ofsub-optimal use instances wherein the application was delivered from asub-optimal location and reporting the sub-optimal use instances to auser of the application.

Any of the embodiments described above further comprising taking anaction to at least partially mitigate the sub-optimal use instance.

Any of the embodiments described above wherein the user is anadministrator.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to determine a delivery location of an application based, atleast in part, upon at least one of manual information collection,triangulation based on source DNS queries and application probing,analyze at least one network traffic flow associated with theapplication to extract data comprising at least one of a user location,a closest application delivery location and a source of user flowservice, aggregate the extracted data to identify a plurality ofsub-optimal use instances wherein the application was delivered from asub-optimal location and report sub-optimal use instances to a user ofthe application.

Any of the embodiments described above further configured to take anaction to at least partially mitigate the sub-optimal use instance.

Any of the embodiments described above wherein the user is anadministrator.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a location of one or more service offeringlocations each hosting a plurality of applications each having anassociated application definition, determining a location of a deviceconfigured to access at least one of the plurality of applications andtransmitting to the device an application definition for each of theapplications to which the device has access, wherein the applicationdefinition is based, at least in part, on the location of one or moreservice offering locations and the location of the device.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to determine a location of one or more service offeringlocations each hosting a plurality of applications each having anassociated application definition, determine a location of a deviceconfigured to access at least one of the plurality of applications andtransmit to the device an application definition for each of theapplications to which the device has access, wherein the applicationdefinition is based, at least in part, on the location of one or moreservice offering locations and the location of the device.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to receive application data flow information from a spokedevice within a network that is associated with an enterprise site andtransmit a traffic profile to the enterprise site based at least in parton a current network data flow characteristic.

Any of the embodiments described above wherein a data transfer controlover the network is at least one of application based and policy based.

Any of the embodiments described above further comprising applyingtime-based application domain classification and mapping to determiningsteps.

Any of the embodiments described above wherein the network comprisesconnectivity selected from the group consisting of hybrid, physical andlogical.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein at least one applicationcomprises a data center application.

Any of the embodiments described above wherein the policy string formatis standardized.

Any of the embodiments described above wherein routing is based, atleast in part, on a dynamic and automated QoS definition.

Any of the embodiments described above wherein applications are selectedfrom the group consisting of transactional applications and filetransfer applications.

Any of the embodiments described above further comprising employing QoSstandardized controls selected from the group consisting of shaping,policing, random early discard, tail drop, low latency queues, anomalyqueues, fair queues and buffers.

Any of the embodiments described above further utilizing parameters tocategorize data flows.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises allocating an identifier to each of a plurality of policieseach comprising a network-isolation identifier associated with a VXWANdirective and transmitting each of the plurality of policies to one ormore devices in a network.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to allocate an identifier to each of a plurality of policieseach comprising a network-isolation identifier associated with a VXWANdirective and transmit each of the plurality of policies to one or moredevices in a network.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving each of a plurality of policies at a networkeddevice wherein each policy comprises a network-isolation identifierassociated with a VXWAN directive and inserting the network-isolationidentifier into one or more packets transmitted by the networked device.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device is configured to receive each of the plurality of policieswherein each policy comprises a network-isolation identifier associatedwith a VXWAN directive and insert the network-isolation identifier intoone or more transmitted packets.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving from a first network tenant an indication of apartner network tenant with which to establish a IPSEC VPN tunnel, atleast one of a site associated with the partner network tenant to whicha IPSEC VPN TUNNEL is to be established, source prefixes at a tenantsite from to which application traffic is allowed to travel over theIPSEC VPN TUNNEL and destination prefixes for application traffic thatcan travel over the IPSEC VPN TUNNEL, receiving an indication from thepartner network tenant of agreement to establish the IPSEC VPN TUNNELand instructing one or more devices of the first network and the partnernetwork to establish an IPSEC data tunnel between themselves.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to receive from a first network tenant an indication of apartner network tenant with which to establish a IPSEC VPN TUNNEL, atleast one of a site associated with the partner network tenant to whicha IPSEC VPN TUNNEL is to be established, source prefixes at a tenantsite from to which application traffic is allowed to travel over theIPSEC VPN TUNNEL and destination prefixes for application traffic thatcan travel over the IPSEC VPN TUNNEL, receive an indication from thepartner network tenant of agreement to establish the IPSEC VPN TUNNELand instruct one or more devices of the first network and the partnernetwork to establish an IPSEC data tunnel between themselves.

Any of the embodiments described above wherein the network comprisesconnectivity selected from the group consisting of hybrid, physical andlogical.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein the policy string formatis standardized.

Any of the embodiments described above wherein encryption is employed.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises detecting a data flow and an associated originating interfaceon a network, determining a first link over which to forward the dataflow, transmitting the data flow over the determined link, receiving areturn data flow and moving a forward direction of the return data flowto a new path if the return data flow arrived via a link other than thefirst link wherein all packets following a first packet on the flow areforwarded on the same path as the first packet.

Any of the embodiments described above further comprising storing thedetermined first link at an L4 level in a flow table.

Any of the embodiments described above wherein the data flow is detectedvia a SYN or a detected UDP session.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device is configured to detect a data flow and an associatedoriginating interface on a network, determine a first link over which toforward the data flow, transmit the data flow over the determined link,receive a return data flow and move a forward direction of the returndata flow to a new path if the return data flow arrived via a link otherthan the first link wherein all packets following a first packet on theflow are forwarded on the same path as the first packet.

Any of the embodiments described above further configured to store thedetermined first link at an L4 level in a flow table.

Any of the embodiments described above wherein the data flow is detectedvia a SYN or a detected UDP session.

Any of the embodiments described above further comprising applyingtime-based application domain classification and mapping to determiningsteps.

Any of the embodiments described above further comprising modelingapplication sessions and predicting bandwidth requirements.

Any of the embodiments described above wherein data flows are employedvia SYN.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a plurality of network segments comprising anetwork, determining a manner in which the plurality of segments areconnected, determining network segments and how segments are connected,at least in part, without a routing protocol, discovering a plurality ofexternal network segments via a hub device associated with the networkand utilizing the plurality of network segments comprising the network,the manner in which the plurality of segments are connected and theplurality of external network segments.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to determine a plurality of network segments comprising anetwork, determine a manner in which the plurality of segments areconnected, determine network segments and how segments are connected, atleast in part, without a routing protocol, discover a plurality ofexternal network segments via a hub device associated with the networkand utilize the plurality of network segments and addresses comprisingthe network, the manner in which the plurality of segments are connectedand the plurality of external network segments to establish at least oneforwarding rule.

In accordance with an exemplary and non-limiting embodiment, a systemcomprises a multi-tenant controller configured to create a networkdescription of a network and a HUB device forming a part of the networkand configured to execute a routing protocol with at least one otherdevice resulting in network information and to communicate the networkinformation to the multi-tenant controller, wherein the multi-tenantcontroller is configured to merge the network information with thenetwork description.

Any of the embodiments described above wherein the network topologyidentification, simulation and load testing is controlled by themulti-tenant controller.

Any of the embodiments described above further comprising detectingasymmetric network data traffic and associated network devices.

Any of the embodiments described above wherein the network comprisesconnectivity selected from the group consisting of hybrid, physical andlogical.

Any of the embodiments described above wherein there are employedrouting protocols selected from the group consisting of BGP, IS-IS,EIGRP and OSPF.

Any of the embodiments described above wherein routing is based, atleast in part, on a network prefix type.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises monitoring a plurality of network devices to collect networkperformance data comprising data flow records of each device on thenetwork and to create a network topology database, accessing the networktopology database comprising information on an entry and exit point ofeach device, the manner in which the devices are connected and aplurality of data flow records on a single data flow from multipledevices on the network and utilizing the network topology database toperform an asymmetric detection algorithm to identify one or more dataflows that exited a device via a first path and returned to the devicevia a different second path.

Any of the embodiments described above wherein a controller isconfigured to receive information and detect asymmetry.

Any of the embodiments described above wherein detection is based, atleast in part, on latency attributes.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein asymmetry is selectedfrom the group consisting of bandwidth asymmetry, media access asymmetryand loss rate asymmetry.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises detecting at a device an application having an anchor domain,marking the application with a traffic source having an entry pointdomain that accessed the application and a time of detection anddesignating network flows from the traffic source within a predeterminedtime from the time of detection as belonging to the application.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device is configured to detect an application having an anchordomain, mark the application with a traffic source having an entry pointdomain that accessed the application and a time of detection anddesignate network flows from the traffic source within a predeterminedtime from the time of detection as belonging to the application.

Any of the embodiments described above further comprising modelingapplication sessions and predicting bandwidth requirements.

Any of the embodiments described above further comprising performinganomalous session identification, quarantine and restriction.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving from a networked spoke device information describingnetwork flows to and from an application, analyzing the information tocharacterize the application in at least one dimension selected from thegroup consisting of bi-directional bandwidth usage, network responsetimes, application response times, a number of idle and activeapplication sessions and a maximum number of concurrent applicationsessions and transmitting the dimensions to at least one networked spokedevice as traffic profile information.

Any of the embodiments described above wherein the information describesL4 level network flows.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to receive from a networked spoke device informationdescribing network flows to and from an application, analyze theinformation to characterize the application in at least one dimensionselected from the group consisting of bi-directional bandwidth usage,network response times, application response times, a number of idle andactive application sessions and a maximum number of concurrentapplication sessions and transmit the dimensions to networked spokedevices as traffic profile information.

Any of the embodiments described above wherein the information describesL4 level network flows.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises modeling a transactional application operating in a networkedenvironment by a size of transactions and a frequency of transactionswith a set distribution to produce one or more modeled parameters andanalyzing the modeled parameters to predict a data flow size andfrequency of one or more transactional application sessions.

Any of the embodiments described above wherein the set distribution isselected from the group consisting of normal, Weibull and Pareto.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises modeling a bulk application operating in a networkedenvironment by a size of transactions and a frequency of transactionswith a set distribution and analyzing the modeled parameters to predictthe frequency of one or more bulk application sessions.

Any of the embodiments described above wherein the set distribution isselected from the group consisting of normal, Weibull and Pareto.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises modeling an application operating in a networked environmentby a size of transactions and a frequency of transactions with a setdistribution to produce one or more modeled parameters, detecting, basedat least in part on the modeling, a hybrid application trafficcharacteristic, wherein the hybrid application traffic characteristiccomprises a first data traffic type that is correlated with at least onedata traffic characteristic of a transactional application and a seconddata traffic type that is correlated with at least one data trafficcharacteristic of a bulk application and analyzing the modeledparameters to predict a data flow size and frequency of one or morehybrid application sessions.

Any of the embodiments described above wherein the set distribution isselected from the group consisting of normal, Weibull and Pareto.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises sending network usage data relating to an application usagesession from a configurable device to a multi-tenant controller, whereinthe network usage data comprises a first type of data flow associatedwith an application and a second type of data flow associated with theapplication, identifying a bandwidth requirement for each of the firstand second types of data flows associated with the application based, atleast in part, on historical data relating to the performance of theapplication and an associated data flow, storing within the multi-tenantcontroller the bandwidth requirement as an application bandwidthprofile, sending the application bandwidth profile to at least one spokedevice and using the application bandwidth profile to route data flowsassociated with the application.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein routing is based, atleast in part, on a dynamic and automated QoS definition.

Any of the embodiments described above wherein applications are selectedfrom the group consisting of transactional applications and filetransfer applications.

Any of the embodiments described above further comprising employingmodeling and analytics selected from the group consisting of Pareto andWeibull.

Any of the embodiments described above further utilizing parameters tocategorize data flows.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises issuing a tuned request on a specified active link having aningress shaper and an egress shaper to a server utilizing a linkcapacity to an extent in both a forward path and a return path,determining a link capacity for the active link, monitoring the activelink and dropping any traffic traveling via the active link when a limitof at least one of the ingress shaper and the egress shaper is exceeded.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises issuing a request on a specified active link having andingress shaper and a egress shaper to a server utilizing a link capacityto an extent in both a forward path and a return path, determining alink capacity for the active link, monitoring the active link,determining a limit of the ingress shaper and the egress shaper based,at least in part, using bandwidth estimation logic and dropping anytraffic traveling via the active link when the limit is exceeded.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving a plurality of business priority classes, detectinga network type associated with each of a plurality of application dataflows in a network wherein the network data flow types are selected formthe group consisting of real-time, bulk and transactional, creating aplurality of strict priority queues, fair queues and anomaly queues foreach of the plurality of business priority classes and assigningreal-time network data flows to real-time queues, transactional flows tofair queues and bulk flows to bulk fair queues.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises monitoring a bandwidth of an application comprising anapplication session at a configured spoke device at a predetermined timeinterval and adjusting the bandwidth such that the bandwidth matches arequirement of the application session while meeting the requirements ofone or more defined business priorities.

Any of the embodiments described above further employing a multi-tenantcontroller based mapping of a user or device identity to a network levelidentity.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein routing is based, atleast in part, on a dynamic and automated QoS definition.

Any of the embodiments described above further comprising employingmodeling and analytics selected from the group consisting of Pareto andWeibull.

Any of the embodiments described above further comprising employing QoSstandardized controls selected from the group consisting of shaping,policing, random early discard, tail drop, low latency queues, fairqueues, anomaly queues and buffers.

Any of the embodiments described above further utilizing parameters tocategorize data flows.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises executing at a controller a horizontally scalable serviceIdentity Definitions Manager (IDM) Service, mapping active directory(AD) domains to WAN network elements DNS ROLE and LDAP ROLE, instructinga plurality of network elements associated with a tenant to discover aplurality of AD domains and AD servers in an enterprise using the DNSROLE, receiving from the plurality of network elements running DNS ROLEinformation indicative of changes to network attributes selected fromthe group consisting of AD domains, additions and subtractions of ADservers and changes in an IP address of AD servers, transmitting thereceived AD domains and AD servers to a tenant administrator andrequesting credentials to communicate with added AD servers using LDAP,executing an algorithm to determine which element will contact specificAD instances to minimize lightweight directory access protocol (LDAP)traffic volume occurring on the WAN and to ensure AD instances can stillbe reached in case of failure of any one network element, monitoring inActive Directory servers changes in at least one identity (user orgroup) of a network user by using the LDAP ROLE on the network elementsand updating a policy, based at least in part on the mapping of useridentity in AD domains, at a multi-tenant controller, wherein thetracking of changing identity information is implemented as ahorizontally scalable service the Identity Definitions Manager Service.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to run at a controller a horizontally scalable serviceIdentity Definitions Manager (IDM) Service, map active directory (AD)domains to WAN network elements DNS ROLE and LDAP ROLE, instruct aplurality of network elements associated with a tenant to discover aplurality of AD domains and AD servers in an enterprise using the DNSROLE, receive from the plurality of network elements running DNS ROLEinformation indicative of changes to network attributes selected fromthe group consisting of AD domains, additions and subtractions of ADservers and changes in an IP address of AD servers, transmitting thereceived AD domains and AD servers to a tenant administrator andrequesting credentials to communicate with added AD servers using LDAP;and execute an algorithm to determine which element will contactspecific AD instances to minimize lightweight directory access protocol(LDAP) traffic volume occurring on the WAN and to ensure AD instancescan still be reached in case of failure of any one network element,receive from the LDAP ROLE of network element changes in ActiveDirectory servers in at least one identity (user or group) of a networkand update a policy, based at least in part on the mapping of useridentity in AD domains, at a multi-tenant controller, wherein thetracking of changing identity information is implemented as ahorizontally scalable service the Identity Definitions Manager Service.

In accordance with an exemplary and non-limiting embodiment, a networkelement executing DNS ROLE and LDAP ROLE configured to obtaininstructions from a central multi-tenant controller IDM server on whichdomains to discover AD servers in using DNS role, discover using DNSROLE information indicative of changes to network attributes selectedfrom the group consisting of AD domains, additions and subtractions ofAD servers and changes in an IP address of AD servers, and transmittingthis information to the multi-tenant controller IDM service, receivefrom the multi-tenant controller IDM service the credentials tocommunicate with discovered AD servers using LDAP and monitor in ActiveDirectory servers changes in at least one identity (user or group) of anetwork user by using the LDAP ROLE on the network elements andtransmitting these changes to the multi-tenant controller IDM service.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises executing at a controller a horizontally scalable service IPto Site Mapping (ISM) Service, instructing a plurality of networkelements associated with a tenant to discover a plurality of AD domainsand AD servers in an enterprise, receiving from the plurality of networkelements information indicative of changes to network attributesselected from the group consisting of AD domains, additions andsubtractions of AD servers and changes in an IP address of AD servers,transmitting the received AD domains and AD servers to a tenantadministrator and requesting credentials to communicate with added ADservers using WMI, executing an algorithm to determine which elementwill contact specific AD instances in order to contain WMI communicationover LAN and minimize WMI communication over WAN, monitoring, using theWMI role on the network elements, the AD servers security login eventscomprising an IP address, a user AD ID and a user name, converting thelogin events to IP-to-user events and transmitting these to the ISMservice in the controller, using the ISM service to map these IP-to-userevents to the right spoke site, sending the events with enrichedinformation comprising one or more group IDs for the user to the elementin the spoke site and using the enriched IP to user event at the spokesite to enforce policy based on user and group IDs and to enrich flowand application statistics with user and group information.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller for controlling a plurality ofassets across a plurality of distributed computing environments whereinthe controller is configured to execute at a controller a horizontallyscalable service IP to Site Mapping (ISM) Service, instruct a pluralityof network elements associated with a tenant to discover a plurality ofAD domains and AD servers in an enterprise, transmit the received ADdomains and AD servers to a tenant administrator and requestingcredentials to communicate with added AD servers using WMI, transmit thecredentials to the network elements running WMI ROLE, execute analgorithm to determine which element will contact specific AD instancesin order to contain WMI communication over LAN and minimize WMIcommunication over WAN, receive from the elements a plurality of ADserver login events which contain user IP address, user AD ID and username, convert these login events to IP-to-user events and transmittingthese to the ISM service in the controller using the ISM service to mapthese IP-to-user events to the right spoke site, send these events withenriched information comprising a group ID for the user to the elementin the spoke site and use the enriched IP to user event at the spokesite to enforce policy based on user and group IDs and to enrich flowand application statistics with user and group information.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises obtaining instructions from a central multi-tenantcontroller's IDM service to discover a plurality of AD domains and ADservers in an enterprise using DNS ROLE, transmitting information to amulti-tenant controller IDM indicative of changes to network attributesselected from the group consisting of AD domains, additions andsubtractions of AD servers and changes in an IP address of AD servers,receiving credentials from the multi-tenant controller to communicatewith added AD servers using WMI, monitoring, using the WMI role, the ADservers security login events comprising an IP address, a user AD ID anda user name and converting the login events to IP-to-user events andtransmitting the login events to an ISM service in a controller.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving enriched IP to user event at a spoke site from amulti-tenant controller's IP to Site Mapping Service to enforce policybased, at least in part, on a user and a group ID and enriching flowstatistics and application statistic with user and group information.

Any of the embodiments described above further utilizing a networkidentity type.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving information describing an addition of a first sitecomprising at least one application to an existing network wherein theinformation is selected from the group consisting of type of site,planned connectivity to the site and planned policies for the site; andestimating an impact on the operation of the at least one applicationand associated network traffic using statistical analysis of monitoreddata collected from a second site similar to the first site.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving information describing a change to a policy for anexisting network wherein the information is selected from the groupconsisting of the policy to be changed and the network sites to whichthe policy is to apply and estimating an impact on the operation of theat least one application and associated network traffic usingstatistical analysis of monitored data collected from a second sitesimilar to the first site.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving information describing a new network link to beadded to an existing network site wherein the information is selectedfrom the group consisting of the site and the network link to be addedand estimating an impact on the operation of the at least oneapplication and associated network traffic using statistical analysis ofmonitored data collected from a second site similar to the first site.

Any of the embodiments described above wherein the application analysisis performed on a per session basis.

Any of the embodiments described above wherein a branch type is selectedfrom the group consisting of retail store bank, POS device, anddistributed computing site.

Any of the embodiments described above wherein at least one applicationcomprises a data center application.

Any of the embodiments described above wherein applications are selectedfrom the group consisting of transactional applications and filetransfer applications.

Any of the embodiments described above further comprising performingmodeling and analytics selected from the group consisting of Pareto andWeibull.

Any of the embodiments described above wherein a network type isselected from the group consisting of wired and wireless.

Any of the embodiments described above further utilizing parameters tocategorize data flows.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving at a branch device an assigned first hub device andan assigned second hub device associated with a data center,establishing a VPN data tunnel to the assigned first and second hubdevices, designating the first hub device as a primary device anddesignating the second hub device as a secondary device and switchingtraffic destined for the primary device to the secondary device based,at least in part, on a cost of a link.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving at a branch device an assigned first hub device andan assigned second hub device associated with a data center,establishing a VPN data tunnel to the assigned first and second hubdevices, designating the first hub device as a primary device,designating the second hub device as a secondary device, switchingtraffic destined for the primary device to the secondary device if afailure of the VPN data tunnel to the primary device is detected andswitching traffic to the primary device and the secondary device in arevertive mode and non-revertive mode.

A networked branch device configured to receive at a branch device anassigned first hub device and an assigned second hub device associatedwith a data center, establish a VPN data tunnel to the assigned firstand second hub devices, designate the first hub device as a primarydevice, designate the second hub device as a secondary device and switchtraffic destined for the primary device to the secondary device if afailure of the VPN data tunnel to the primary device is detected.

Any of the embodiments described above further comprising switchingtraffic destined for the primary device to the secondary device based,at least in part, on a cost of a link.

Any of the embodiments described above wherein the first hub device andsecond hub device are assigned via an algorithm based, at least in part,on:

-   -   data transfer statistics information collected from the branch        device used as an input to estimate traffic load.    -   internet link bandwidth estimation performed at the branch        device used as input to estimate traffic load.    -   the current known capacity limits of each hub device.    -   the current allocated branch devices to each hub device in a        cluster and the sum of their estimated load on the hub device.    -   the current allocated branch devices to each hub device in a        cluster and the actual load on the hub device.    -   availability of total capacity of a hub cluster.    -   network reachability of the new branch device to the all the        elements of the hub cluster.    -   ability to use all branch circuits when communicating with hub        device.    -   ability to use lower cost circuits when communicating with hub        device.

Any of the embodiments described above wherein configurable devicescomprise spoke devices.

Any of the embodiments described above wherein a data center type isselected from the group consisting of private cloud, scientificcommunities and co-location centers.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises deploying in series a plurality of configurable devicesconfigured to communicate with one another via a protocol for exchangingstate information wherein at least one of the plurality of configurabledevices is in an active state and at least one of the plurality ofdevices is in a standby state, detecting, by the at least one of theplurality of configurable devices in a standby state, a failure of aconfigurable device in an active state via a protocol and switching theat least one configurable device in a standby state to an active state.

In accordance with an exemplary and non-limiting embodiment, a systemcomprises a plurality of configurable devices deployed in series andconfigured to communicate with one another via a protocol for exchangingstate information wherein at least one of the plurality of configurabledevices is in an active state and at least one of the plurality ofdevices is in a standby state wherein the at least one of the pluralityof configurable devices in a standby state is adapted to detect afailure of a configurable device in an active state via a protocol andin response thereto switch the at least one configurable device in astandby state to an active state.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises deploying in series a plurality of configurable devicesconfigured to communicate with one another via a protocol for exchangingstate information wherein at least one of the plurality of configurabledevices is self-selected to be in an active state and at least one ofthe plurality of devices is in a standby state, detecting, by the atleast one of the plurality of configurable devices in a standby state, afailure of a configurable device in an active state via a protocol andswitching the at least one configurable device in a standby state to anactive state.

Any of the embodiments described above wherein connectivity is physical

Any of the embodiments described above wherein branch components areselected from the group consisting of switches and routers.

Any of the embodiments described above wherein configurable devicescomprise spoke devices.

Any of the embodiments described above wherein switch types are selectedfrom the group consisting of managed switch, unmanaged switch andstackable switch.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises generating at a multi-tenant controller a common shared secretfor establishing a link between a first site and a second site,transmitting the shared secret to each of the first site and the secondsite over a secured channel, assigning a wall clock based start and endvalidity period for the shared secret, sending the shared secret with afuture validity to allow secure link communication to continue if one ormore elements in both sites cannot communicate with the multi-tenantcontroller and using a separate shared secret per link per VXWAN

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving at a first channel end point a shared secret,generating a plurality of nonce values, exchanging the nonce values witha second channel end point, generating a plurality of session keys andrefreshing the plurality of session keys at a predetermined timeinterval using the shared secret.

In accordance with an exemplary and non-limiting embodiment, a systemcomprises a first site, a second site in communication with the firstsite via a network and a multi-tenant controller configured to generatea common shared secret for establishing a link between the first siteand the second site and to transmit the shared secret to each of thefirst site and the second site over a secured channel wherein themulti-tenant controller is configured to assign a wall clock based startand end validity period for the shared secret.

Any of the embodiments described above wherein shared secret generationis performed by software, hardware and/or a software and hardwarehybrid.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presenttechnology may be realized by reference to the figures, which aredescribed herein.

FIG. 1A provides a simplified schema of the layers within a data networkarchitecture.

FIG. 1B illustrates a simplified embodiment of an architecture employinga multi-tenant controller is association with a plurality of networkfacilities and devices.

FIG. 1C illustrates a simplified embodiment for forwarding applicationdata flows in accordance with a detected network status.

FIG. 1D illustrates a simplified embodiment for utilizing applicationsignatures in association with policy strings.

FIG. 1E illustrates a simplified embodiment for analyzing data trafficflows to detect sub-optimal network performance.

FIG. 2 Illustrates a sample embodiment of using a multi-tenantcontroller to provide a policy, such as a network performance policy, inassociation with a VXWAN to encapsulate and encrypt specified data flowsaccording to a policy.

FIGS. 3A and 3B depict network data flows between configured deviceswhere certain linkages between network devices are unavailable.

FIG. 4 illustrates a sample embodiment for determining network segmentsfor the purpose of establishing a data forwarding rule or policy.

FIG. 5 illustrates simplified examples of asymmetry in data flows over anetwork and the use of a multi-tenant controller for detecting andcorrecting such asymmetric data flows.

FIG. 6 illustrates a simplified embodiment of establishing an anchordomain based at least in part on a plurality of data flows.

FIG. 7 depicts a sample embodiment showing the usage of a shaper tocontrol data congestion and data flows in association with aconfigurable device.

FIG. 8A illustrates the usage of a shaper to detect and respond to datacongestion within a network and actions that may be taken.

FIG. 8B illustrates a simplified view of network components comprisingdynamic bandwidth control.

FIG. 9 Illustrates one embodiment of the multi-tenant controller withina network used to monitor, record and store IP-to-user data mappings andusing such mappings to direct data flows over a network based at leastin part on user identity.

FIG. 10 illustrates a simplified embodiment for using statisticalanalysis to approximate and evaluate application performance on anetwork site.

FIG. 11 illustrates a simplified embodiment for using hub pairs andconfigurable devices to create network scaling and redundancy.

FIG. 12 illustrates a simplified embodiment of a configurable devicepairing.

FIG. 13 illustrates a simplified embodiment of a method for utilizing ashared secret to generate an application session key.

FIGS. 14 and 15 illustrate a simplified embodiment of the use ofprefixes and associated automated learning.

FIG. 16 illustrates a simplified seamless deployment model within a datacenter.

FIG. 17 illustrates a simplified embodiment of a multicast deploymentthat includes a multi-tenant controller.

FIGS. 18 and 19 illustrate a simplified embodiment of data trafficoccurring over two MPLS providers.

FIG. 20 illustrates a simplified embodiment of data traffic occurringover an MPLS provider and a VPN.

DETAILED DESCRIPTION

Referring to FIG. 1A, data networks, such as those used by largecorporate enterprises and services providers, are modeled as eightnetwork layers to describe the methods and systems of the presentinvention described herein. Within this framework, Layer 1 is thephysical layer 120 consisting of basic networking hardware and datatransmission infrastructure. Networking hardware may be deployed withina network across a plurality of physical sites, including but notlimited to a data center 128, such as a distributed cloud computingnetwork, and branch 152 locations that are connected to the data center128. Data center 128 type as used herein includes, but is not limitedto, a private cloud (e.g., Amazon or Google), a scientific community(e.g., a national laboratory), co-location centers, in-house datacenters, or some other type of data center. Data centers 128 may beclassified as Tier I, Tier II, Tier III and Tier IV.

Branches 152 may connect to data center 128 through physical or logicalconnectivity 150. Physical connectivity 148 may include, but is notlimited to, a T1 link, such as that from a branch 152 to multiprotocollabel switching (MPLS 144), or connectivity through a cable, orconnectivity through DSL, or connectivity through wireless and cellularnetworks. Logical connectivity 150 may include, but is not limited to, aprivate wide area network (WAN) or a virtual private network (VPN).Connectivity may also be a hybrid, for example, a physical connectivity148, through a T1 link, to the Internet 142 that includes elements oflogical constructs. In an example, hardware, such as a multi-tenantcontroller 122 that controls switches, routers 162, hub devices, spokedevices, configurable devices 124, or some other hardware type may bedeployed within a data center 128. A multi-tenant controller 122 as theterm is used herein may refer to a multi-tenant, single-tenant, and/orplurality of associated single-tenant or multi-tenant controllers. Aspoke device as the term is used herein may include, but is not limitedto a branch device, each of which may be a configurable device 124, asdescribed herein. A hub device as the term is used herein may refer to ahub device that is routed, in-path, distributed and load balanced,and/or distributed, load-balanced and routed. Switch as used hereinincludes, but is not limited to, a managed switch (e.g., a smart switchor enterprise-managed switch), an unmanaged switch, a stackable switch,or some other switch type. Device as the term is used herein mayinclude, but is not limited to, a hardware device, software device,physical device, virtual device or logical device.

Branches 152 may route data, data packets and other information to andfrom a data center 128 through, for example the Internet 142 or MPLS144. Branches 152 may also route data, data packets and otherinformation to and from Applications 148, Ad Networks 134 and ContentDelivery Networks 138 through, for example the Internet 142 or MPLS 144.The Internet 142 may include a private cloud and be less expensive, butalso less secure, than MPLS 144. MPLS 144 may include a private WAN.Examples of branch 152 types include, but are not limited to, a retailstore, a bank store front, a data input point, such as a point-of-saledevice, remote offices of an enterprise, and distributed computingsites.

Layer 2 of a data network is referred to as the data link layer 118.This layer includes the functional elements that enable the transfer ofdata, such as data units consisting of frames, from one network entityto a second network entity. Physical addressing of network elements alsoresides within Layer 2. The Media Access Control (MAC) sub layercontrols how a computer on the network gains access to the data andpermission to transmit it and the Logical Link Control (LLC) layercontrols frame synchronization, flow control and error checking.

Layer 3 of a data network is referred to as the network layer 114. It isat this layer that functionality such as packet forwarding occurs, aswell as elements of routing protocol management. Forwarding at thislayer is packet-based as opposed to based on, for example data flowsdefined by occurring within an application session, as described herein.Routing protocols may include, but are not limited to, static routes,Border Gateway Protocol (BGP), Intermediate System-to-IntermediateSystem Protocol (IS-IS), Enhanced Interior Gateway Routing Protocol(EIGRP), and Open Shortest Path First (OSPF). Routing protocols providea mapping of reachable network endpoints (IP Addresses) and theavailable network interfaces and paths available to reach them.

Layer 4 of a data network is referred to as the policy driven flow andsession forwarding layer 112. Logical addressing, multiplexing, dataflow control, packet fragmentation and reassembly may occur at thislayer. Data forwarding and path selection at this layer may be based onPolicy. A Policy specifies the treatment that should be offered to theapplication flow or application session, including choice of networkpaths. Policies thus provide a filtered set of network paths from Layer3 available to an application or user at a network device.

Data forwarding and path selection at this layer may be based upon anapplication session. As used herein, a “session” refers to one or moreflows identified as belonging to a client 512 accessing a specificapplication. As used herein, “client device” refers to a laptopcomputer, desktop computer, tablet computer, phone, smart phone, server,PDA, smart watch, wearable device, or some other type of client devicecapable of computing and/or interacting with a data network, asdescribed herein. As used herein, a “flow” refers to a stream of packets(bidirectional) associated with a single session. As used herein,“packets” refer to the basic unit of data transfer in a network. As usedherein, “session-flow” refers to any flow belonging to an identifiedsession. Current solutions at this layer may be limited because theydefine applications by, for example, IP addresses or port numbers. Portnumbers are not workable in cloud environments. For example, anapplication like Microsoft Exchange (Outlook email) may be served out ofa port 135. When an email is delivered as a service from acloud-computing environment, such as Gmail, Yahoo and the like, theclient device 164 used may primarily connect over HTTPS (port 443). Itis likely that many cloud-based applications are delivered through thesame HTTPS port 443. Thus, the port information alone is not sufficientto define the application. The concept of an “application session,” andthe ability to define and identify an application session has utilitybecause existing solutions are imprecise in determining the data flowsthat are associated with a given application. Existing solutionstypically measure performance on those flows, which includes jitter,bandwidth (BW) and other metrics. “Flow” and “data flow” as used hereinmay include, but are not limited to a connection, TCP connection,transaction, application transaction, 3-way handshake, connections persecond or CPS, session, application session, bi-directional exchange,bi-directional flow, unidirectional flow (e.g., in UDP based dataexchanges), mixed flows, channels, netflow, concurrent flows, or someother type of data flow. A flow may consist of multiple packets, and asession may consist of multiple flows. Various parameters may be used tocategorize data flows including, but not limited to, transactional,transactional real time and the like.

According to the methods and systems of the present invention describedherein, a flow may be detected as belonging to an application, but alsoas belonging to an application session. An application session maycollate different flows originating from same source and mark them asbelonging to a session. Some of these flows may appear to be acompletely different application, when in fact they are really not.Performance measurements may be cohesively used on all the flowsbelonging to a session, thus improving actual application performanceand control. For example, some applications may not be impacted bypacket loss. In another example, round-trip latency might not berelevant to applications that require multiple round trips for properapplication performance. Latency issues may include, but are not limitedto, geographical diversity of Internet connectivity, network trafficvolume, the distance between a client 512 and a server, and packet loss.For example, packet loss may be caused by natural “lossiness” of thelink/connectivity or due to network volume that causes congestion andthus increases packet loss. In an embodiment, an application session maybe defined as a time frame, for example data derived from Time 1 to Time2. In another embodiment, an application session may be defined as thetime occurring between a user 168 logging in to use an application, andlogging out to discontinue use of the application. In another example,an application session may be defined as data derived from activitiesthat are considered related applications or sites, such as websites. Forexample, the Office365 application may include data flows to anOffice365 portal, an Office365 Sharepoint, Lync or some other relatedservice or site.

Layer 5 of a data network is referred to as the application reachabilityforwarding layer 110. Application-based forwarding may occur at thislayer, and may be based on “reachability.” Reachability refers to apoint of differentiation within forwarding where the issue is not “can Ireach a particular IP address through a specific path/connectivity,” butinstead “can I reach an application and can I do so in a manner that isconsistent with a policy regarding the application.” Enterprises may usemultiple connectivity choices. For example, an enterprise may use MPLS144 plus a Comcast Internet connection (i.e., a hybrid connectivity) fordata routing. Layer 5 thus provides a filtered set of network paths fromLayer 4 available to an application based on reachability.

Layer 6 of a data network is referred to as the application performanceforwarding layer 108. Application based forwarding may be based onperformance. A user's 168 Internet point of presence (POP) might begeographically diverse. This can create a latency problem (slowerperformance). A configured device and controller may monitorapplications of interest to user 168 and adjusts selectable paths andforwards traffic based on application performance. Controller as theterm is used herein refers to a multi-tenant controller. Forwardingdecisions taken may be carried out consistent with a policy, withconnectivity permissions, or some other rule or criterion. Layer 6 thusprovides a filtered set of network paths from Layer 5 available to anapplication based on applications performance on one or more networkpaths.

Layer 7 of a data network is referred to as the application and userlayer 104. This is where applications and users operating over thenetwork resides. The traffic from user to application and fromapplication to user enters at this layer and based on the final filteredset of network paths for that application and user, an appropriate pathis chosen for forwarding.

Layer 8 of a data network is referred to as the operator layer 102. Thisis where the network operators reside, such as an IT administrator thatis responsible for setting user-based policies, generating reports, orsome other administrative function.

In accordance with exemplary and non-limiting embodiments, and referringto FIG. 1B, a multi-tenant controller 122 may be associated with aconfigured device within a data network. The multi-tenant controller 122and the configured device may have physical or logical connectivity 150with a plurality of facilities, including but not limited to, a datacenter 128 or a plurality of data centers 128, an ad network 134, acontent delivery network 138, and third party data and applications 140.Data centers 128 within the network in this simplified example, and withwhich the multi-tenant controller 122 may communicate, may have hubdevices, additional configured devices and/or applications 132, withwhich the multi-tenant controller 122, and/or configured deviceassociated with the multi-tenant controller 122, may communicate. Adnetworks 134, content delivery networks 138, and third party data andapplications 140 may provide data into the network, such as pairing anadvertisement with a web content delivery to a client device 164, thedata of which may be recognized, tracked and recorded by themulti-tenant controller 122, and/or the configured device that isassociated with the multi-tenant controller 122. Data within the networkmay derive from a branch 152 of the network, such as a physical officeor store of an enterprise. A branch 152 may have network facilities,including but not limited to, a shaper 154, a device switch 158, anapplication 132, a configured device, a server 160, a router 162, orsome other network facility or device. The branch 152 may communicatewith other facilities within the network, such as the data center 128 orthe multi-tenant controller 122, through the Internet 142 or MPLS 144,using physical or logical connectivity 150. A user 168 of the networkmay interact with a client device 164 to access the network, forexample, a user 168 may use a computing tablet, such as an iPad, tointeract with a bank branch 152 in order to transfer money from one bankaccount to another. As described herein, a multi-tenant controller 122,including in conjunction with a configured device, may monitor thenetwork activity, record and store such activity for the purpose ofoptimizing the flow of traffic over the network so that it is consistentwith a policy, such as a policy indicating that a certain type of dataflow (e.g., “sensitive banking data”) be given preferential routingrelative to less important data (e.g., “Internet banner advertisements),or some other type of policy.

In traditional networks, applications used in enterprises have differentlevels of need from a wide area network (WAN). Available WAN solutionsforward traffic primarily based on reachability information and at bestdo so utilizing data indicative of link level conditions such as packeterror rates and packet loss rates.

Legacy networks, especially WANs, connect locations or sites. Thesesites may be remote offices or branches 152 and data centers 128.Typically, applications reside in these data centers 128 and users 168access these applications through the network. If a specific applicationneeds differential treatment either for quality of service (QoS) orrouting (e.g., want to send certain application traffic through acertain location), the only way to achieve this was to manuallytranslate that application to a network identity, typically an IPaddress or IP address range, and then manipulate routers 162 and routingprotocols to achieve the intent (differential treatment).

The complexity surrounding such manipulation and achievement of thebusiness intent can be enormous, and mostly involves a “change and pray”approach. Policy based security/firewalls and policy based routing hasbeen in place for a while. Firewalls mostly use policies to allow/denytraffic, and, in some cases, allowed traffic to be given forwarding/pathconstraints. Typically, router devices 162 use “routemaps” which allowcertain packets matched by IP address and packet lengths to beclassified and treated according to some policy specifications. Thesepolicy specifications allow for choice of the next-hop destination foreach packet. Therefore there is a need for methods and systems fordetermining the location-based distribution of applications and relateddefinitions, path characterizations and the dynamic characterization ofapplications for determining optimal, policy-based path selection ofapplication traffic flows across the available network assets.

In accordance with exemplary and non-limiting embodiments, there isprovided a method by which the WAN may adjust to yield to the needs ofapplications in order to provide an optimal or near optimal experienceto the users 168. The production of such an experience begins with therouting of application flows on the most suitable link present at abranch office 152, meeting the needs of an application. Once anapplication flow is placed on an appropriate link, sufficient networkresources may be guaranteed in accordance to a policy specification forthe application flow.

With reference to FIG. 1C, there is illustrated a method according to anexemplary and non-limiting embodiment. First, at step 100C applicationsare identified as are the network requirements of the applications.Then, at step 102C application flows are forwarded appropriately on thevarious available links, based on the current state of the network 528.These forwarding decisions constantly evolve based on the dynamic stateof the network 528.

In accordance with exemplary and non-limiting embodiments, configurablespoke devices perform the traffic forwarding decisions, and are providedthe necessary pieces of information: a) application identificationdetails and b) application traffic profiles.

Each configurable device 124 also maintains the path characterizationinformation. Path characterization may include information on bandwidthavailability on a link, latency profiles, traffic volume caps on a linkand the like. The configurable device 124 may then choose a link meetingall the constraints that is most optimal or most nearly optimal for anapplication at that time instant.

In accordance with exemplary embodiments, application intelligence andunique path characterization details are utilized to choose the mostsuitable link. The multi-tenant controller 122 effectively “understands”what an application is, beyond its IP address, and configurable devices124 at a branch 152 may parse and detect if a specific flow represents aspecific application or not.

As a result, a simple policy model may be implemented by which one canspecify a business intent directly and the multi-tenant controller 122and device together make it happen in the network. Such an expression ofbusiness intent may be, for example: “For Application Salesforce, giveit Gold priority, send it through Atlanta DC”.

With reference to FIG. 1D, there is illustrated a method according to anexemplary and non-limiting embodiment. At step 100D, applicationspecific research yields a signature unique to every application. Inembodiments, an application signature may include a combination of oneor more of the following: (a) Domain name(s), (b) URLs, (c) a ServerNetwork Identity (SNI), (d) a source and/or destination IP address, (e)a source and/or destination port and (f) any sequence of bytes at staticpositions in encrypted or unencrypted flow transactions, (g) anysequence of bytes following a matching previous sequence of bytes inencrypted or unencrypted flow transactions, (h)size/transmission/frequency patters of encrypted flow transactions (i)order and pattern of flow establishment and data relative to other flowsseen.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises determining a signature for each of a plurality ofapplications based, at least in part, on at least one of a domain name,a URL, a Server Network Identity (SNI), source IP address, a destinationIP address, a source port, a destination port, including any sequence ofbytes at static or dynamic positions in encrypted or unencrypted flowtransactions, any sequence of bytes following a matching previoussequence of bytes in encrypted or unencrypted flow transactions, size,transmission, frequency patters of encrypted flow transactions, orderand pattern of flow establishment and data relative to other flows seenand HTTP metadata, transmitting each of the signatures to a branchdevice 152 and transmitting a policy string 202 defining a businesspolicy to be applied to a data flow exhibiting the signature to thebranch device 152.

In accordance with an exemplary and non-limiting embodiment, a methodcomprises receiving a signature for each of a plurality of applicationsbased, at least in part, on at least one of a domain name, a URL, aServer Network Identity (SNI), source IP address, a destination IPaddress, a source port, a destination port, including any sequence ofbytes at static or dynamic positions in encrypted or unencrypted flowtransactions, any sequence of bytes following a matching previoussequence of bytes in encrypted or unencrypted flow transactions, size,transmission, frequency patters of encrypted flow transactions, orderand pattern of flow establishment and data relative to other flows seenand HTTP metadata, receiving at least one policy string 202 defining abusiness policy, analyzing at least one network data flow to detect thepresence of the signature and applying the business policy to the atleast one network data flow comprising the detected signature.

In accordance with an exemplary and non-limiting embodiment, a centrallycontrollable multi-tenant controller 122 for controlling a plurality ofassets across a plurality of distributed computing environments isconfigured to determine a signature for each of a plurality ofapplications based, at least in part, on at least one of a domain name,a URL, a Server Network Identity (SNI), source IP address, a destinationIP address, a source port, a destination port, including any sequence ofbytes at static or dynamic positions in encrypted or unencrypted flowtransactions, any sequence of bytes following a matching previoussequence of bytes in encrypted or unencrypted flow transactions, size,transmission, frequency patters of encrypted flow transactions, orderand pattern of flow establishment and data relative to other flows seenand HTTP metadata, transmit each of the signatures to a branch device152 and transmit a policy string 202 defining a business policy to beapplied to a data flow exhibiting the signature to the branch device152.

In accordance with an exemplary and non-limiting embodiment, a networkedbranch device 152 is configured to receive a signature for each of aplurality of applications based, at least in part, on at least one of adomain name, a URL, a Server Network Identity (SNI), source IP address,a destination IP address, a source port, a destination port, includingany sequence of bytes at static or dynamic positions in encrypted orunencrypted flow transactions, any sequence of bytes following amatching previous sequence of bytes in encrypted or unencrypted flowtransactions, size, transmission, frequency patters of encrypted flowtransactions, order and pattern of flow establishment and data relativeto other flows seen and HTTP metadata, receive at least one policystring 202 defining a business policy, analyze at least one network dataflow to detect the presence of the signature and apply the businesspolicy to the at least one network data flow comprising the detectedsignature.

In accordance with various embodiments, these application signatures aregenerated and published to the multi-tenant controller 122. In practice,the customer may use whatever method he/she is naturally inclined toutilize. In some embodiments, customers may specify the signature indomain name/urls as applications are increasingly becoming web oriented.

Next, at step 102D, the multi-tenant controller 122 may push theapplication signatures to configurable branch devices 124. Everyconfigurable device 124 has the capability to parse every flow that goesthrough the configurable device 124 and detect the presence of theapplication signature as the flow starts.

Once matched, additional functions can be applied to the flow. Finally,at step 104D, the multi-tenant controller 122 exposes an API throughwhich the network admin/user can define a POLICY STRING 202 to expressthe Business Intent as follows:

-   -   <APP>, <IDENTITY>--<PRIORITY>, <SERVICE>, <VXWAN>, <PATH>    -   Where,    -   APP—Application name/id, provided by provider of configured        devices or custom defined by network admin/user    -   IDENTITY—User name/id or Device id, optional    -   PRIORITY—Business Priority for the <APP, IDENTITY> combination    -   SERVICE—Service(s) that should be provided for the <APP,        IDENTITY> combination, optional    -   VXWAN—Virtual WAN isolation identifier for the <APP, IDENTITY>        combination, optional. Examples include, but are not limited, to        a network isolation identifier.    -   PATH—Path constraints for the <APP, IDENTITY> combination,        optional

As used herein, “policy string” 202 defines, generally, who can connectto what application with what kind of priority. “Business Priority”refers to the abstraction of quality of service (QoS) into categories.In exemplary embodiments, a standardized policy string 202 format may beutilized. In accordance with an exemplary and non-limiting embodiment, acentrally controllable multi-tenant controller 122 for controlling aplurality of assets across a plurality of distributed computingenvironments may be configured to allocate a network-isolationidentifier to each of a plurality of policies that contains the sameVXWAN directive and transmit each of the plurality of policies with thatnetwork-isolation identifier to one or more devices in a network. Anetwork-isolation identifier as used herein includes, but is not limitedto, a virtual network identifier (VNI), segment identifier, and/ornetwork identifier. A network-isolation identifier may be or may includenumeric data, alphabetic data, and/or alphanumeric data. A policyidentifier may include a network-isolation identifier.

With the capabilities described above, every branch configurable device124 may look for the application signature associated with anapplication, and when detected, enforces the Policy as follows:

-   -   PRIORITY Enforces priority queues, similar to classic QoS,        within the device and specific to the interface on which the        flow is exiting and entering the device. The enforcement happens        in a bidirectional manner affecting the download and upload        directions, thus causing the flow and thus the application to        operate within the bounds of the PRIORITY intent.    -   SERVICE Forwards the flow, and thus the application, to a        specific service. A SERVICE, which is defined separately, could        be reached from the device through normal L3 forwarding, or        through an L3 tunnel, or be defined as a recipient of the copy        of the flow. In the latter case, the configured device makes a        copy of every packet of the flow in both directions, and sends        it to the service, wherever it may exist in the network. The        other two services are expected to be in the path of the flow        and thus the flow is forwarded towards that Service through        normal L4→L3 forwarding.    -   VXWAN As the flow is forwarded, the configured device can        optionally add a “VXWAN” label/encapsulation, which is a Virtual        WAN Identifier. This VXWAN 204, similar to VXLAN in the data        center 128, has applications beyond just encapsulation.    -   PATH Path directive, if present, constrains the paths the flow        for the APP and/or IDENTITY specified in the policy, is allowed        to take as the flow exits the configured device.

VXWAN 204 allows customers to create several small, isolated overlaytunnels over the same physical underlay. Each tunnel may be encryptedwith a different set of keys, such that even if keys of one of thetunnels is compromised, others are not exposed. From a customer'sperspective, VXWAN 204 allows customers to create isolated networksegments end to end (with VLANs in the branch 152 and DCs, and VXWAN 204in the WAN). This helps in setting operational boundaries between thevarious teams in the enterprise, securing the various parts of networkinfrastructure independently, and meet various regulatory compliancerequirements, such as PCI.

Advantages associated with these embodiments include a policy string 202used for business intent and not for just choosing the next hop orsecurity treatment. Further, currently implemented solutions lack theconcept of VXWAN 204. In addition, while certain security products haveused APP and IDENTITY for the purposes of local security enforcement andhave separately provided a way to direct traffic on specific interfaces,the described method goes beyond this such that the APP and IDENTITY areused to specify the network treatment of the flow across the entire WAN.

From a routing perspective, a server 160 or a next hop may be reachableeven though an application is not available on the path. For example, anHTTP proxy sitting on a path may be having performance issues and may beblocking connections. From a routing perspective, this blocking will notbe seen as a failure and packets will continue to be forwarded to theproxy. It is further possible that the latency on a path is so high thatan application is effectively unusable while operation of theapplication on a different path would be fine. In embodiments, anapplication may also reside in the Internet, such as possibly with an AdNetwork 134, Content Delivery Network 138, or Third Party DataApplications 140.

In accordance with exemplary and non-limiting embodiments, applicationlevel probing ensures that an application is reachable and usable by auser 168 at all times. Configurable spoke devices perform “app probing”,where the configurable spoke device 124 periodically checks for thehealth of the applications on all of the paths. The configurable device124 may then rate the links from best path to worst path, and providethis information to the multi-tenant controller 122.

Upon receiving the information, the multi-tenant controller 122 may usethe information to route application flows. Rating of the links may beas simple as ordering by the lowest network latency, or may be assophisticated as considering application level transaction latencies.

In accordance with exemplary embodiments, active probing and rating thenetwork paths may be performed in the context of each application (e.g.,box.com) or sub-application (e.g., office365-lync, office365-sharepoint)for SaaS services. In the case of enterprise applications, activeprobing may be performed on the specific servers 160 of an application,as there can be many application delivery end points in an enterprise.For example, for Server Message Block (SMB) (file share) applications,there may be many servers 160 that serve an application with differentcontent.

As described herein, active probing differs from generic probing such asis typically practiced. When employing generic probing, a typical pingto a known server may get through (establishing L3 connectivity) evenwhen a connection to the server 160 may not be established. Byestablishing a session with the server 160 via active probing, presentembodiments establish application level connectivity.

In accordance with various embodiments, there may be performed a serverlevel check, in the context of applications. For example, someapplications like SMB have a service end point per server 160, unlike aSAAS service where there can be many servers 160 backing a single HTTPservice. The applications in the former category are internal enterpriseapplications. For this category of applications, one may monitor at aserver level. In some scenarios it is even possible that a single servermay host multiple services, like SMB and HTTP. In that case, the sameserver will be probed for each service end point. In other words, theprobing is done actual service delivery endpoint to make sure that theapplication is accessible.

In some scenarios, the location from which an application is served isless than optimal. This is often the case with SAAS apps whereapplications may be delivered from multiple locations, e.g., westernUnited States, eastern United States, the European Union, Latin America,etc. In such cases, it is often best to send such application flowsinitiated by a user 168 at a branch 152 to the closest possible appdelivery location. In practice, this may not happen due to, for example,(1) the location of DNS servers and query points, (2) sub-optimalpolicies and (3) the unavailability of information related toapplication delivery locations.

With reference to FIG. 1E, there is illustrated a method according to anexemplary and non-limiting embodiment. First, at step 100E, according toexemplary embodiments, SAAS application delivery locations may beidentified via (1) manual information collection and feeding the system,(2) triangulation based on sourcing DNS queries from various locationsacross the globe and (3) information collected through app-probing asdescribed above.

After collecting such information, at step 102E, the system may applyanalytics by a component of the multi-tenant controller 122 on allobserved traffic flows and extract the following three pieces ofinformation: (1) where is the user 168 located (based on siteinformation), (2) where is the closest application delivery location(using the above set of data) and (3) where was the user flow servicedfrom.

Then, at step 104E, the system may then (1) aggregate instances wherethe application was delivered from a sub-optimal location (based onoriginating geographic location), (2) recognize patterns and (3) ifthere is significant and consistent sub-optimal use, reports such use toa user, such as the administrator, of the multi-tenant controller 122.

In an exemplary and non-limiting embodiment, the methods and systemsdescribed herein may be applied to address and remediate instances ofsub-optimal use.

As a result, there is provided (1) automatic application servicedelivery location learning, (2) a geo-IP based approach to determine theactual application delivery location and (3) identification andreporting of sub-optimal selection of service delivery location.

In accordance with exemplary embodiments, the definition of applicationsmay be performed on a per-site basis based, at least in part, ongeography. In such instances, application detection profiles may bedefined by system operators/administrators and/or customers. Theseprofiles may then be propagated from the multi-tenant controller 122 toconfigurable devices 124 so that the configurable devices 124 can detectapplications.

SAAS applications 604 typically have service/application offeringlocations distributed around the globe. When a user 168 accesses anapplication, they are directed to the closest service offering location.Because different service offering locations have different HTTP domainnames, application definitions need to include the domain names.

In accordance with exemplary embodiments, instead of uniformlydistributing an application definition with all of the domain names toall of the configurable devices 124, the application definition may becustomized based on the location of the configurable device 124 to whichit is distributed.

For example, one may send the application definition “eu.xforce.com” toa device in Europe, and “na.xforce.com” to a device in North America.Definitions sent to configurable devices 124 are customized based, atleast in part, on the location of the configurable device 124.

In accordance with exemplary and non-limiting embodiments, eachconfigurable spoke device 124 may collect and report statistics from thesite where located to the multi-tenant controller 122. The multi-tenantcontroller 122 may then send back a traffic profile to the configurabledevice 124 applicable to the site. For new sites, for which a trafficprofile may not exist, the system may choose the most common trafficprofile for distribution and then customize it for the site soon after.In some embodiments, measurements of throughput from a server 160 to anend point may be normalized by subtracting out the server 160contribution and normalizing the time in flight based on the size of atransaction. Thus, there is provided a method for the dynamic andon-going characterization of applications on a per site basis andadjusting the behavior of the network in response thereto. In accordancewith exemplary embodiments, the methods described herein may be appliedto transactional applications including, but not limited to, chatprograms, VoIP, video conferencing and screen sharing programs.

In accordance with various exemplary embodiments, methods and systemsfor network traffic characterization described above may utilizephysical connectivity 148, logical connectivity 150 or hybridconnectivity as described elsewhere herein. Furthermore, such methodsand systems may be applied to application sessions as described above.Such methods and systems as described herein may be utilized by and forall manner of data center 128 applications as described herein.

In accordance with various exemplary embodiments, methods and systemsfor network traffic characterization described above may utilize dynamicautomated QoS definition as described herein. Exemplary embodiments mayutilize file transfer applications and QoS standardized controls asdescribed herein. Other exemplary embodiments may utilize parameters forcategorizing data flows as described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   determining a network requirement for at least one application;    -   dynamically determining a link suitable for data transmission in        accordance with a policy based at least in part on a current        network condition to meet the network requirement; and    -   routing one or more application network data flows associated        with the at least one application over the link.

A method comprising:

-   -   determining a network requirement for at least one application;    -   determining a link suitable to meet the network requirement        based, at least in part, on at least one of a plurality of        application identification details and an application traffic        profile; and    -   routing one or more application network data flows associated        with the at least one application over the link.

Any of the clauses above wherein the application is operating at a node.

Any of the clauses above wherein the application is operating at abranch.

Any of the clauses above wherein dynamically determining the link isperformed by a configurable spoke device.

Any of the clauses above wherein the configurable spoke device maintainspath configuration information.

Any of the clauses above wherein path configuration information isselected from the group consisting of bandwidth availability on a link,a latency profile and a traffic volume cap.

A method comprising:

-   -   determining a signature for each of a plurality of applications        based, at least in part, on at least one of a domain name, a        URL, a Server Network Identity (SNI), source IP address, a        destination IP address, a source port, a destination port, any        sequence of bytes in one of a static position and a dynamic        position in encrypted or unencrypted flow transactions, any        sequence of bytes following a matching previous sequence of        bytes in encrypted or unencrypted flow transactions, at least        one of a size, a transmission and a frequency pattern of        encrypted flow transactions, an order and a pattern of flow        establishment and data relative to other flows seen and HTTP        metadata;    -   transmitting each of the signatures to a branch device; and    -   transmitting a policy string defining a business policy to be        applied to a data flow exhibiting the signature to the branch        device.

A method comprising:

-   -   receiving a signature for each of a plurality of applications        based, at least in part, on at least one of a domain name, a        URL, a Server Network Identity (SNI), source IP address, a        destination IP address, a source port, a destination port, any        sequence of bytes at one of a static position and a dynamic        position in encrypted or unencrypted flow transactions, any        sequence of bytes following a matching previous sequence of        bytes in encrypted or unencrypted flow transactions, at least        one of a size, a transmission and a frequency pattern of        encrypted flow transactions, an order and a pattern of flow        establishment and data relative to other flows seen and HTTP        metadata;    -   receiving at least one policy string defining a business policy;    -   analyzing at least one network data flow to detect the presence        of the signature; and applying the business policy to the at        least one network data flow comprising the detected signature.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   determine a signature for each of a plurality of applications        based, at least in part, on at least one of a domain name, a        URL, a Server Network Identity (SNI), source IP address, a        destination IP address, a source port, a destination port, any        sequence of bytes at one of a static position and a dynamic        position in encrypted or unencrypted flow transactions, any        sequence of bytes following a matching previous sequence of        bytes in encrypted or unencrypted flow transactions, at least        one of a size, a transmission and a frequency pattern of        encrypted flow transactions, an order and a pattern of flow        establishment and data relative to other flows seen and HTTP        metadata;    -   transmit each of the signatures to a branch device; and    -   transmit a policy string defining a business policy to be        applied to a data flow exhibiting the signature to the branch        device.

A networked branch device configured to:

-   -   receive a signature for each of a plurality of applications        based, at least in part, on at least one of a domain name, a        URL, a Server Network Identity (SNI), source IP address, a        destination IP address, a source port, a destination port, any        sequence of bytes at one of a static position and a dynamic        position in encrypted or unencrypted flow transactions, any        sequence of bytes following a matching previous sequence of        bytes in encrypted or unencrypted flow transactions, at least        one of a size, a transmission and a frequency pattern of        encrypted flow transactions, an order and a pattern of flow        establishment and data relative to other flows seen and HTTP        metadata;    -   receive at least one policy string defining a business policy;    -   analyze at least one network data flow to detect the presence of        the signature; and    -   apply the business policy to the at least one network data flow        comprising the detected signature.

Any of the clauses above wherein the policy string comprises elementsselected from the group consisting of a user identity, a SERVICE, a pathand a VXWAN.

A method comprising:

-   -   checking at a predetermined interval a status of one or more        network paths to a remotely located application;    -   rating the relative status of each of the one or more network        paths wherein the rating is based at least in part on at least        one of network latency and an application level transaction        latency; and    -   utilizing the rating to route an application data flow        associated with the application.

A networked branch device configured to:

-   -   check at a predetermined interval a status of one or more        network paths to a remotely located application;    -   rate the relative status of each of the one or more network        paths wherein the rating is based at least in part on at least        one of network latency and an application level transaction        latency; and    -   utilize the rating to route an application data flow associated        with the application.

Any of the clauses above wherein the rating of the network paths is inthe context of an operability of an application.

Any of the clauses above wherein the rating of the network paths isfurther based, at least in part, on a bandwidth of the path, a MOSscore, a packet loss and jitter.

A method comprising:

-   -   determining a delivery location of an application based, at        least in part, upon at least one of manual information        collection, triangulation based on source DNS queries and        application probing;    -   analyzing at least one network traffic flow associated with the        application to extract data comprising at least one of a user        location, a closest application delivery location and a source        of user flow service;    -   aggregating the extracted data to identify a plurality of        sub-optimal use instances wherein the application was delivered        from a sub-optimal location; and    -   reporting the sub-optimal use instances to a user of the        application.

Any of the clauses above further comprising taking an action to at leastpartially mitigate the sub-optimal use instance.

Any of the clauses above wherein the user is an administrator.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   determine a delivery location of an application based, at least        in part, upon at least one of manual information collection,        triangulation based on source DNS queries and application        probing;    -   analyze at least one network traffic flow associated with the        application to extract data comprising at least one of a user        location, a closest application delivery location and a source        of user flow service;    -   aggregate the extracted data to identify a plurality of        sub-optimal use instances wherein the application was delivered        from a sub-optimal location; and    -   report sub-optimal use instances to a user of the application.

Any of the clauses above configured to take an action to at leastpartially mitigate the sub-optimal use instance.

Any of the clauses above wherein the user is an administrator.

A method comprising:

-   -   determining a location of one or more service offering locations        each hosting a plurality of applications each having an        associated application definition;    -   determining a location of a device configured to access at least        one of the plurality of applications; and    -   transmitting to the device an application definition for each of        the applications to which the device has access, wherein the        application definition is based, at least in part, on the        location of one or more service offering locations and the        location of the device.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   determine a location of one or more service offering locations        each hosting a plurality of applications each having an        associated application definition;    -   determine a location of a device configured to access at least        one of the plurality of applications; and    -   transmit to the device an application definition for each of the        applications to which the device has access, wherein the        application definition is based, at least in part, on the        location of one or more service offering locations and the        location of the device.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   receive application data flow information from a spoke device        within a network that is associated with an enterprise site; and    -   transmit a traffic profile to the enterprise site based at least        in part on a current network data flow characteristic.

Any of the clauses above wherein a data transfer control over thenetwork is at least one of application based and policy based.

Any of the clauses above further comprising applying time-basedapplication domain classification and mapping to determining steps.

Any of the clauses above wherein the network comprises connectivityselected from the group consisting of hybrid, physical and logical.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein at least one application comprises adata center application.

Any of the clauses above wherein the policy string format isstandardized.

Any of the clauses above wherein routing is based, at least in part, ona dynamic and automated QoS definition.

Any of the clauses above wherein applications are selected from thegroup consisting of transactional applications and file transferapplications.

Any of the clauses above further comprising employing QoS standardizedcontrols selected from the group consisting of shaping, policing, randomearly discard, tail drop, low latency queues, anomaly queues, fairqueues and buffers.

Any of the clauses above further utilizing parameters to categorize dataflows.

In traditional networking, adequately partitioning network traffic canbe problematic. Partitioning may be done based at least in part on, butnot limited to, routing uniqueness, security criteria, or networkisolation. Using existing techniques, partitioning is typicallyimplemented by virtual local area networks (VLANs) and virtual routingand forwarding (VRFs). VLANs and VRFs may be linked manually, where themanual linkage is at the branches 152 and data centers 128. This manuallinkage may provide network isolation across a wide area network (WAN),but there exists a need for controlling data flows in a policy-basedmanner that is application-specific and/or identity specific, where theimplementation of the policy, and related data flow rules, is embodiedin a device that is centrally controlled by a multi-tenant controller122. The multi-tenant controller 122 may be further used to establishextranet IPSEC VPN tunnels between separate enterprises (and associatednetworks).

According to the methods and systems of the present invention describedherein, a software defined enterprise WAN (SDEwan) may be used to createa network that is embodied in an application network driven model. Abusiness intent of the model may be expressed through a policy string202. A policy string 202 may allow a specific application or identity tobe specified that provides control over data flows occurring over thenetwork. Control may be per-application, per-identity, a combination ofapplication and identity, or based on some other parameter. In anembodiment, as part of a policy string 202, a virtual extensible WAN(VXWAN) 204 may be specified that causes a device to encapsulate aspecific set of flows identified by that policy in a unique VXWAN 204. AVXWAN 204 may comprise a network-isolation identifier or label that maybe put on the wire as data/packets belonging to the flows captured bythe policy are forwarded between devices. A VXWAN 204 may comprise anoptional unique encryption afforded only to packets belonging to theflows captured by the policy. A VXWAN 204 may comprise a way to insert aVXWAN network-isolation identifier at an entry point in the network andremove the network-isolation identifier at the exit in the network forthe flow in a specific direction. A VXWAN 204 may be bidirectional inthat the same VXWAN network-isolation identifier can be used for bothdirections of the traffic. A VXWAN network-isolation identifier namespace may be global and allocated and managed by a multi-tenantcontroller 122, as defined herein.

In embodiments, a network administrator may specify a policy for anapplication or identity, or application-identity combination. This mayinclude a VXWAN directive and may also include the type of path to take,including but not limited to the Internet 142, a private WAN, a wirelessroute, and, for example, whether to use encryption or not. Encryption asused herein includes, but is not limited to, standard encryptionmethods, differentiated encryption methods, advanced encryptionstandard, OpenPGP, CipherSaber, or Triple Data Encryption Algorithm. Apolicy may also specify a priority level to be given to an identity,application or identity-application combination. For example, a policymay provide that all PCI applications, irrespective of the VLAN on whichthey arrive, on the LAN side, should be placed on a PCI VXWAN. Inanother example, a policy may provide that all traffic from voice VLANbe placed on a voice VXWAN. Examples of identities include, but are notlimited to a user group, executive user group, specific individual(e.g., Tim Jones the CEO), specific enterprise department (e.g.,Finance), or some other identity.

According to the methods and systems of the present invention describedherein, and referring to FIG. 2, a multi-tenant controller 122 may beprovided and used to implement a policy, policy string 202, or someother rule-based operation governing data flows over a network. Amulti-tenant controller 122 may allocate a numeric network-isolationidentifier or label from a namespace it manages for a tenant. Thecontroller may send policies to devices in the network, and suchpolicies may have VXWAN 204 specified and include any network-isolationidentifiers allocated by the multi-tenant controller 122. As a deviceidentifies the application and identity of data flows entering andexiting the device, it may apply the policies it received from themulti-tenant controller 122. If a VXWAN network-isolation identifier ispresent for a policy, the data path software on the device may insertthe label on the wire as the packets of the flow exit the device. If theVXWAN 204 is an encrypted VXWAN, then a policy-specific encryption maybe applied before the packets of the flow exit the device. At the otherend of the data flow, the receiving device may de-cap, for example, thesending device may place the VXWAN header on the packet with the VXWANnetwork-isolation identifier. The receiving device may remove the VXWANheader, remove the VXWAN network-isolation identifier from the header,and pass the packet to either a specific virtual routing and forwarding(VRF) on the core router 178, or to a global VRF on the core router 178.Examples of policy strings 202 include, but are not limited to, examplesprovided in the following table:

VXWAN (possibly, including, without limitation, a network- isolationNetwork Context App User Paths Allowed Business Priority identifier)Guest WiFi Any Any direct internet 142 P4 None Any PCI applications AnyVpn, private wan P1 PCI Voice VLAN Any Any Vpn, privatewan P1 voice AnyAny CEO Vpn, privatewan P1 CEO

In embodiments, a multi-tenant controller 122 may be used to establishExtranet IPSEC VPN tunnels between two separate enterprises, sites ornetworks. The multi-tenant controller 122 may be used to indicate withwhich other tenant and to which site of the other tenant they want IPSECVPN tunnels established. The multi-tenant controller 122 may alsospecify which prefixes in each of a plurality of sites can communicatewith each other. In an example, the IT administrator of a tenant mayindicate to the multi-tenant controller 122 the partner tenant to whichthey want to establish a VPN, to which site of the partner they want theVPN to occur, their own site which should participate in the VPN, thesource prefixes or specific IPs in their site from which applicationtraffic is allowed to go over the IPSEC VPN tunnels, and the destinationprefixes or specific IPs for the application traffic which can go overthe IPSEC VPN tunnels. Once the IT administrator of the partner tenantagrees to the request to allow creation of IPSEC VPN tunnels between theenterprises, the multi-tenant controller 122 may instruct the devices oneach of the sites of the two enterprises to establish an IPSEC datatunnel between the two sites. This may further restrict the enterprisesto allow traffic only between those source and destination prefixes thatwere specified by the administrators of the two tenants. In embodiments,the most restrictive subset of the allowed prefixes may be used on bothsides. Examples of prefixes include, but are not limited to, 10.1.1.0/20and 192.168.2.1/24.

In accordance with various exemplary embodiments, methods and systemsfor application and policy based network data transfer control describedabove may utilize physical connectivity 148, logical connectivity 150 orhybrid connectivity as described elsewhere herein. Furthermore, suchmethods and systems may be applied to application sessions as describedabove and may employ a standardized policy string 202 format andencryption.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   allocating an identifier to each of a plurality of policies each        comprising a network-isolation identifier associated with a        VXWAN directive; and    -   transmitting each of the plurality of policies to one or more        devices in a network.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   allocate an identifier to each of a plurality of policies each        comprising a network-isolation identifier associated with a        VXWAN directive; and    -   transmit each of the plurality of policies to one or more        devices in a network.

A method comprising:

-   -   receiving each of a plurality of policies at a networked device        wherein each policy comprises a network-isolation identifier        associated with a VXWAN directive; and    -   inserting the network-isolation identifier into one or more        packets transmitted by the networked device.

A networked branch device configured to:

-   -   receive each of the plurality of policies wherein each policy        comprises a network-isolation identifier associated with a VXWAN        directive; and    -   insert the network-isolation identifier into one or more        transmitted packets.

A method comprising:

-   -   receiving from a first network tenant an indication of a partner        network tenant with which to establish a IPSEC VPN tunnel, at        least one of a site associated with the partner network tenant        to which a IPSEC VPN TUNNEL is to be established, source        prefixes at a tenant site from to which application traffic is        allowed to travel over the IPSEC VPN TUNNEL and destination        prefixes for application traffic that can travel over the IPSEC        VPN TUNNEL;    -   receiving an indication from the partner network tenant of        agreement to establish the IPSEC VPN TUNNEL; and    -   instructing one or more devices of the first network and the        partner network to establish an IPSEC data tunnel between        themselves.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   receive from a first network tenant an indication of a partner        network tenant with which to establish a IPSEC VPN TUNNEL, at        least one of a site associated with the partner network tenant        to which a IPSEC VPN TUNNEL is to be established, source        prefixes at a tenant site from to which application traffic is        allowed to travel over the IPSEC VPN TUNNEL and destination        prefixes for application traffic that can travel over the IPSEC        VPN TUNNEL;    -   receive an indication from the partner network tenant of        agreement to establish the IPSEC VPN TUNNEL; and    -   instruct one or more devices of the first network and the        partner network to establish an IPSEC data tunnel between        themselves.

Any of the clauses above wherein the network comprises connectivityselected from the group consisting of hybrid, physical and logical.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein the policy string format isstandardized.

Any of the clauses above wherein encryption is employed.

In traditional networks, devices make next-hop routing decisions fordata at the packet level. Routing protocols are used to exchange routinginformation between devices. However, local networks often times need tobe manually configured via network statements or redistribution for eachrouting protocol so that prefixes can be advertised to other routingpeers.

In accordance with various exemplary and non-limiting embodiments, thereis provided a method for reducing and/or eliminating asymmetric sessionflows using a flow table to determine a forwarding path based, at leastin part, on the direction of incoming traffic in order to eliminate toeliminate asymmetric flows (each direction of flows taking two differentpaths) and/or packet looping. As described below, flow tables may bemaintained at the configurable device 124.

Network failures may cause transient or semi-permanent asymmetry afteran application flow has started. In the present instance, “asymmetry”refers to the different paths traffic takes in the forward and reversedirection as it is sent and received. In some instances, networkasymmetry can adversely impact the performance of feedback-basedtransport protocols such as Transmission Control Protocol (TCP).

Even if the network path in the direction of session flow isuncongested, congestion in the opposite direction can disrupt the flowof feedback leading to poor performance. Furthermore, troubleshootingthe underlying causes of congestion may pose a problem as one may needto consult the routing tables at each device to see which path is takenby each direction of session flow traffic.

Analysis of asymmetry at the “TCP flow” level may cause significantperformance issues and visibility challenges for security devices likefirewalls. Devices need to see all the traffic on the network tofunction properly, but when asymmetry occurs not all the traffic passesthrough the device due to rerouting. As a result, firewalls, forexample, may only “see” one side of the traffic.

With reference to FIG. 3A, there is illustrated an example of networkflow between two configured devices labeled as “A” and “D” as thesession flows amongst various nodes “B”, “C”, “E” and “F”. Asillustrated, network flow proceeds from A→B→C→D where A and D areconfigured devices.

With reference to FIG. 3B, there is illustrated an example wherein thenetwork link between nodes C and D is broken. In such an instance, theflow may take an alternate path from C→F→D. Consequently, the reversedirection flow from node D to node A may instead take path D→F→E→A. Inthis scenario, at node A, the configurable device 124 observes that theflow was sent to node D through node B but came back from node D vianode E. In response, the configurable device 124 at node A mayautomatically make a path switch decision and commence to send the flowin both directions through node E on its way to node D thuspreserving/enforcing symmetry. Note that it is possible for a transitionperiod to exist where the packets on a flow may be received on bothpaths. In that case the packets on the old path are still received andforwarded to the client, while the new packets in both directions takethe new path. Also, a hold down period is employed after switching pathsbefore another path switching decision is taken. This helps in avoidingflaps due to packets in transit and stale packets.

In accordance with exemplary and non-limiting embodiments, configurabledevices 124 maintain flow-based tables. Flow-based tables are similar torouting tables and forwarding information base (FIB) tables used bylegacy routers 162 to forward packets. As used herein, “flow-basedtables” are tables that allow configurable devices 124 to determinewhich interface a flow was forwarded on in one direction.

As a result, the configurable device 124 can detect an anomaly arisingwhen a detected reverse path is not the same. Received packets may beidentified as being associated with a given flow based on the fivetuples of a packet, specifically, (1) protocol, (2) source IP address,(3) source port, (4) destination IP address, and (5) destination port.Every packet may be identified using the above parameters as belongingto a flow.

The configurable device 124 may next proceed to make decisions for thedetected anomalous flow to move the forward direction of the flow to anew path, thus preventing any further asymmetry for the flow. Ananomalous flow, for example that arises from an application session, maybe detected, mapped, monitored and stored at a configurable device, asdescribed herein, and/or associated with an identity, such as a useridentity or group identity. An anomalous flow, for example that arisesfrom an application session, may be detected, mapped, monitored andstored at a multi-tenant controller, as described herein, and/orassociated with an identity, such as a user identity or group identity.

Note that configurable devices 124 maintaining flow-based tables anddetecting asymmetry is separate from the manner in which themulti-tenant controller 122 detects asymmetry. Multi-tenant controller122 based asymmetry operates on a larger time scale and can detectnetwork level asymmetry rather than interface (configurable device)level asymmetry. Network level asymmetry may happen when, for example,prefixes assigned to a site are “moved” to a new site and traffic flowstake inefficient and sometimes asymmetric paths.

In accordance with exemplary embodiments, sites may be assignedpredetermined prefixes, and each configurable device 124 may choose aset of paths to forward a given packet based on the destination IPaddress on the packet and based on the prefixes that have been assignedto a site.

One factor giving rise to asymmetry in such instances is that theprefixes assigned to a site may be incorrect, or were correct at thetime of assignment, but became incorrect due to some changes made in thephysical underlay network. When this happens, the device may choose awrong set of paths, resulting in asymmetry.

By observing flows end-end, the multi-tenant controller 122 may assesswhich flows take these inefficient paths, if they are due to prefixissues and if sufficient evidence and strength or duration of evidenceexists to alert the IT administrator. In an exemplary embodiment, an ITadministrator may configure the multi-tenant controller 122 to takeautomatic action. The multi-tenant controller 122 may then reconfigurethe prefixes to reflect the new site it is believed to belong to.

In embodiments, configurable devices 124 at nodes make forwardingdecisions at the L4-TCP/UDP flow-level. As a result, each flow thatcrisscrosses a network including configurable devices 124 enters andexits configurable devices 124 that forward a specified flow on aspecified path in both forward and reverse directions. As a result, flowsymmetry is preserved.

In exemplary embodiments, L4 flow-based tables may be implemented. Eachflow entering a node may be detected when a synchronize packet (SYN)(for TCP flows) or when a new UDP session (previously unknownserver-client user datagram protocol (UDP) transaction) is seen. Upon asuccessful decision to forward a flow on a specific interface on anetwork path, the originating configurable device 124 remembers itsdecision at the flow level.

Where the traffic belonging to the flow goes through hub device withinthe enterprise network irrespective of the traffic's eventualdestination, the hub device similarly remembers the interface thetraffic arrived in its flow table before forwarding to the traffic toits destination server 160.

When the return flow traffic from server 160 arrives at the configurabledevice 124, instead of blindly choosing the next hop for a packet as atypical router 178 would do, the hub device may look up the flow in itsflow table and forward the flow and all of its packets on the sameinterface that it originally received the flow from.

With the above, the return traffic to the configurable device 124 shouldarrive on the same network the forward traffic was sent and thus on thesame interface the forward traffic was sent. The configurable device 124may look up the flow in its flow table and forward the flow and all ofits packets on the same interface that it originally received the flowfrom the Client. As a result, symmetry is preserved.

Where the traffic belonging to the flow was sent directly to otherdestinations, including but not limited to, Ad Networks 134, ContentDelivery Network 138 and Third-Party Data And Applications 140, or anetwork path that is beyond the access of a configurable device, thetraffic may not flow through the configurable device 124. In such cases,the return traffic to the configurable device 124 should arrive on thesame network the forward traffic was sent and thus on the same interfacethe forward traffic was sent as long as there are no network issues inthe external network. The configurable device 124 may look up the flowin its flow table and forward the flow and all of its packets on thesame interface that it originally received the flow from the Client. Asa result, symmetry is preserved.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   detecting a data flow and an associated originating interface on        a network;    -   determining a first link over which to forward the data flow;    -   transmitting the data flow over the determined link;    -   receiving a return data flow; and    -   moving a forward direction of the return data flow to a new path        if the return data flow arrived via a link other than the first        link;    -   wherein all packets following a first packet on the flow are        forwarded on the same path as the first packet.

Any of the clauses above further comprising storing the determined firstlink at an L4 level in a flow table.

Any of the clauses above wherein the data flow is detected via a SYN ora detected UDP session.

A networked branch device configured to:

-   -   detect a data flow and an associated originating interface on a        network;    -   determine a first link over which to forward the data flow;    -   transmit the data flow over the determined link;    -   receive a return data flow; and    -   move a forward direction of the return data flow to a new path        if the return data flow arrived via a link other than the first        link;    -   wherein all packets following a first packet on the flow are        forwarded on the same path as the first packet.

Any of the clauses above further configured to store the determinedfirst link at an L4 level in a flow table.

Any of the clauses above wherein the data flow is detected via a SYN ora detected UDP session.

Any of the clauses above further comprising applying time-basedapplication domain classification and mapping to determining steps.

Any of the clauses above further comprising modeling applicationsessions and predicting bandwidth requirements.

Any of the clauses above wherein data flows are employed via SYN.

Typical Enterprise wide area networks (WANs) are implemented via routingprotocols. Existing software designed networking (SDN) techniques arecommonly employed in data centers 128 (non-WAN) to pull “networkintelligence” to a central controller leaving simple forwardinginstructions on data path devices. Typically, one cannot employ SDNtechniques to a WAN environment because WAN does not allow for safenetwork behavior and scale.

Specifically, unlike with SDN controller based solutions where there ishigh capacity and resilient connectivity between controller and devices,WAN is notoriously non-resilient and bandwidth availability isproblematic. As a result, (a) having controllers deliver fine grainedbut “simple” instructions to devices all the time is not practical and(b) devices have to work even in the absence of connectivity betweencontroller and themselves, sometimes for an extended period of time.

Typical routing protocols exchange and use three different types ofinformation: (1) network segments and addresses, (2) informationindicative of how the network segments are connected and (3) whichexternal network segments are not controlled by the routing instance.Using such information, typical router devices 162 set up packetforwarding tables 812 to allow packets to move from an incominginterface to an outgoing interface in the direction of its destination.

In accordance with exemplary and non-limiting embodiments, amulti-tenant controller 122 may be utilized to algorithmically determineand establish a loop-free data forwarding model that may include thecreation and management of forwarding tables 812. As described morefully below, this algorithm may account for network failures and adjustthe loop-free data forwarding model to account for asset loss within thenetwork.

As described herein, a centrally configured multi-tenant controller 122may be both the creator and the source of (1) network segments andaddresses and (2) information indicative of how the network segments areconnected. The central multi-tenant controller 122 may then discoverwhat external network segments are not controlled by the routinginstance via a DC or configurable device 124.

For example, a DC/configurable device 124 may run routing protocols likeBorder Gateway Protocol (BGP) to peer with other routingdevices/entities in the DC. These other routing entities may provideinformation about the rest of the network and how they are connected orhow to reach network addresses and segments. The DC/configurable device124 may export this data to the multi-tenant controller 122 periodicallyif there is a change, which the multi-tenant controller 122 may save ina network DB. The same network DB may also store the network descriptionthat the multi-tenant controller 122 created using configurable devices124 and instances. Merging the two, the multi-tenant controller has aview of the entire network without running a routing protocol itself.

The multi-tenant controller 122 may directly set up forwarding tables812 on configured devices so that traffic is forwarded on to the correctinterface.

The result is a loop-free forwarding model wherein various rules areenforced. For example, one rule may require that spokes are nevertransit points. As a result, traffic cannot be forwarded betweenconfigured VPNs or between Private WAN and configured VPNs.

In a traditional network, any available interface or circuit is acandidate to forward traffic on to a destination if routing tablesallow. This requires that (a) there are no misconfigurations and (b)during network changes, there exist no alternate paths that mightaccidentally cause a loop. Traditional networking attempts to preventsuch a situation by configuring “route redistribution rules” and othercarefully selected manual constraints that prevent random interfaces orexit points, such as spokes, from being used to forward traffic. Inaccordance with the embodiments described herein, branch devices 152 maybe restricted from allowing traffic to transit through them thuseliminating one aspect of loop causes.

A second rule may require that the following transits are allowed at aconfigurable device 124: (1) Spoke←→Hub←→Spoke and (2) Spoke←→Hub←→DC/DCTransit/PrivateWAN.

Once a branch/spoke is prevented from forwarding traffic between networksegments as described above, rules are established for DC/configurabledevice 124. Since DC is indeed a transit point for traffic, there is aneed to allow transit traffic. In this manner, traffic may be forwardedbetween (a) system controlled network segments and (b) system controlledand non-system controlled network segments.

A third rule may require that hub to hub transit is not permitted. Whilea HUB device needs to allow transit traffic as described above, allowingdirect transit of traffic between two DC/configurable device 124 mayalso result in loops. This problem may be addressed by using classicrouting protocols such as, for example, BGP, between the DC/configurabledevice 124. However, it may also be addressed by preventing directforwarding between DC/configurable device 124 and instead requiring anexternal non-system controlled network or non-system controlled networksegment between the DC/configurable device 124.

Lastly, a fourth rule may require that each hub has at most one path forany given IP prefix at all times. This rule operates to ensure thattraffic destined to a prefix takes a pre-calculated path and not one ofmany equally available paths.

As a result, the multi-tenant controller 122 automatically creates andmanages forwarding tables 812 in medium to very large networks in ascalable and reliable manner.

In accordance with various exemplary embodiments, configurable device124 connectivity may exhibit physical connectivity 148, logicalconnectivity 150 or hybrid connectivity as described elsewhere herein.

In accordance with various exemplary embodiments, algorithmicdeterminations and the establish of a loop-free data forwarding modeldescribed above may take into consideration latency issues as well asvarious forms of asymmetry and various possible failure conditionsdescribed herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   determining a plurality of network segments comprising a        network;    -   determining a manner in which the plurality of segments are        connected;    -   determining network segments and how segments are connected, at        least in part, without a routing protocol;    -   discovering a plurality of external network segments via a hub        device associated with the network;    -   utilizing the plurality of network segments comprising the        network, the manner in which the plurality of segments are        connected and the plurality of external network segments.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   determine a plurality of network segments comprising a network;    -   determine a manner in which the plurality of segments are        connected;    -   determining network segments and how segments are connected, at        least in part, without a routing protocol;    -   discover a plurality of external network segments via a hub        device associated with the network;    -   utilize the plurality of network segments and addresses        comprising the network, the manner in which the plurality of        segments are connected and the plurality of external network        segments to establish at least one forwarding rule.

A system comprising:

-   -   a multi-tenant controller configured to create a network        description of a network; and    -   a HUB device forming a part of the network and configured to        execute a routing protocol with at least one other device        resulting in network information and to communicate the network        information to the multi-tenant controller, wherein the        multi-tenant controller is configured to merge the network        information with the network description.

Any of the clauses above wherein the network topology identification,simulation and load testing is controlled by the multi-tenantcontroller.

Any of the clauses above further comprising detecting asymmetric networkdata traffic and associated network devices.

Any of the clauses above wherein the network comprises connectivityselected from the group consisting of hybrid, physical and logical.

Any of the clauses above wherein there are employed routing protocolsselected from the group consisting of BGP, IS-IS, EIGRP and OSPF.

Any of the clauses above wherein routing is based, at least in part, ona network prefix type.

Asymmetry in network data flows can cause performance issues and impactusers 168 that access those applications. Asymmetry may also causeflow-aware functions, like firewalls, to fail since they might be ableto detect only one direction of the flow. In legacy network operations,when performance issues arise, network and IT administrators musttroubleshoot the issue. If the issue is caused by asymmetry, theadministrator typically must evaluate the network, device-by-device, toidentify the specific devices that might have been in the path of theaffected data flows, and inspect the routing and forwarding tables 812and then rectify the likely routing configuration that might have causedthe asymmetry. This manual process is slow and may disrupt network usagewhile being performed. What is needed are methods and systems formonitoring application and network data flows, such as may be collectedby a multi-tenant controller 122, and using such data to automaticallyidentify asymmetric flows and identify network devices through which theasymmetric data flows likely traversed.

According to the methods and systems of the present invention describedherein, a multi-tenant controller 122 may maintain a network topology atleast in the form of a network topology database in which the entry andexit points for each device in a network are maintained, andperiodically running an algorithm using this network data to determineasymmetric data flows and the devices associated with such asymmetricdata flows. Asymmetry as the term is used herein includes, but is notlimited to, bandwidth asymmetry, media access asymmetry, path asymmetry,and loss-rate asymmetry (e.g., the structure of a network topology maycreate greater packet loss in data flows traveling one directionrelative to an alternate or reverse direction).

In embodiments, a configured device may collect monitoring data, such asinformation relating to data flows transmitting through a device. Suchdata flow records may carry important information relating to the entryand exit points on a device. As shown in FIG. 5, millions of these dataflow records may be exported from devices throughout the network to themulti-tenant controller 122. The multi-tenant controller 122 may storeinformation, including, but not limited to, a network topology databasethat includes information on the entry and exit points of data flowsoccurring on each network device and how the data flows areinterconnected, and data flow records on a single data flow frommultiple devices in the network.

In embodiments, the multi-tenant controller 122 may use the storednetwork topology 508 and related data flow information to periodicallyrun an “asymmetric detection” algorithm 504 that in essence identifiesthe existence of a plurality of data flows that exited a device throughone path and return data flows that re-entered the device on a differentpath (i.e., asymmetry). In a simplified example as shown in FIG. 5, aBranch B 520 may be associated with a spoke device. A Data Center 1 128may have a Hub Device 1 522, and a Data Center 2 128 may have a HubDevice 2 524. Continuing the example, a connection that is initiatedfrom Branch B 520, intended for a server 160 sitting in Data Center 1,may end up taking a path to Data Center 2, and from Data Center 2 go toData Center 1 (e.g., due to legacy routing reasons, or due tomisconfiguration of IP prefixes available at the two data centers 128),and the return traffic may then go directly from Data Center 1 to BranchB 520. Branch B 520, upon receiving the traffic from Data Center 1, mayimmediately correct so the forward direction of traffic is sent directlyto Data Center 1. This correction may be made on demand, and outside ofthe multi-tenant controller 122. The change may be reported, for exampleby a spoke device, to the multi-tenant controller 122. The multi-tenantcontroller 122 may identify asymmetric flows, and see which data centerdevices participated in the transmission of the flow (which in thisexample are Hub Device 1 522 and Hub Device 2 524), and deduce that theflow is incorrectly going to Hub Device 2 524, and reports this. Themulti-tenant controller 122 may identify the IP address ranges on whichthis asymmetry is happening, aggregate them and report to them to auser, such as an IT administrator, so that the IP prefix configurationmay be corrected on the sites. To prevent false positives, the algorithmmay use additional weighting factors including other devices anddifferent applications and their data flows, before declaring existenceof asymmetry in the network. The multi-tenant controller 122 may readdata flow tables in order to allow the multi-tenant controller 122 todetermine how the data traffic egresses (e.g., data deriving from abranch 152). The asymmetry may be detected, and the multi-tenantcontroller 122 may then notify configured devices, as shown in FIG. 5,and the configured devices may take forwarding actions to ameliorate thedata flow asymmetry.

In accordance with exemplary embodiments, such methods and systems forapplication session modeling and prediction of bandwidth requirementsdescribed herein may be applied to application sessions as describedabove and may address various forms of asymmetry described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   monitoring a plurality of network devices to collect network        performance data comprising data flow records of each device on        the network and to create a network topology database;    -   accessing the network topology database comprising information        on an entry and exit point of each device, the manner in which        the devices are connected and a plurality of data flow records        on a single data flow from multiple devices on the network; and    -   utilizing the network topology database to perform an asymmetric        detection algorithm to identify one or more data flows that        exited a device via a first path and returned to the device via        a different second path.

Any of the clauses above wherein a controller is configured to receiveinformation and detect asymmetry.

Any of the clauses above wherein detection is based, at least in part,on latency attributes.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein asymmetry is selected from the groupconsisting of bandwidth asymmetry, media access asymmetry and loss rateasymmetry.

Traditionally, applications and application data have been defined usingthe domain name of an application. However, this is less thansatisfactory, because there can be many domain name variants used as anentry point to an application, and not knowing all variants mayinterfere with correctly identifying applications. For example, asoftware-as-a-service (SaaS) application webpage may embed widgets thatinvoke HTTP application programmer interface (API) calls to multipledomain names, such as that done by content delivery network 138 (CDN)provider domains, including but not limited to Akamai, Microsoft Azure,and Amazon CloudFront. These widgets may generate additional trafficthat should ideally also be associated with the SaaS application 604that embedded them.

Context can also impact which data flows are considered part of anapplication. For example, an email application that is opened within aweb browser may have windows that are creating data flows by accessingthe mail servers, but there might also be data flows that are created byad servers sending content to the email application. It is a morerepresentative depiction to include such ad traffic flows within what isconsidered part of the application that is the email application since apolicy that is intended to govern traffic from the email applicationwill underestimate the data flow volume if such other flows like adtraffic are not included. Therefore, there is a need for methods andsystems that enable the use of time-based cohesiveness as a determinantof application-based data classification, and time-clustered data flowsto identify domains that are associated with an application, includingan anchor domain that is a high-traffic, or frequently used, entry pointfor usage of an application.

According to the methods and systems of the present invention describedherein, a multi-tenant controller 122 may receive data from configurabledevices 124 indicating which domains are associated with an anchordomain, and assign these domains to a SaaS application 604 so that afuller set of entry points to the SaaS application 604 are known andstored by the multi-tenant controller 122. This may have advantages inmeasuring, monitoring and routing the true data flows associated with aSaaS application 604, whereas traditional techniques may underestimatethe traffic associated with a SaaS application 604 by not recognizingthe full set of domains that are actually generating traffic inassociation with an application. Domain types may include, but are notlimited to, top-level domains 608 (e.g., “.com”), geographic domains(e.g., country domains), and infrastructure domains (e.g., “.arpa”).

Anchor domains as the term is used herein typically refer to entry pointdomains for SaaS applications 604. Anchor domains may be thought of asthe top-level domain 608 and may be used to find sub-domains that areassociated with SaaS applications 604. For example, domains accessedfollowing accessing an anchor domain may be correlated with the anchordomain. In an example, Office365 may have an entry point domain but havemany related domain names (e.g., server1.office365.com). In anotherexample, an email application like Yahoo mail may use multiple mailservers and also have frames that are serving ads to the browser fromother servers 160. The multi-tenant controller 122 may store theseanchor domain-domain associations and a time-distance approach may beused to discover the domains that are associated with the anchor domain.In an example, and referring to FIG. 6, the domains that are accessedwith in a configurable time period after the same client 512 accesses ananchor domain may be correlated with the anchor domain. The correlationtechnique may identify some domains that are not closely related to theanchor domain (e.g. domains accessed from a different tab in the browserwindow) and associate these with the anchor domain. The domainsidentified to be associated with the anchor domain may be sent to themulti-tenant controller 122, and at the multi-tenant controller 122,further processing may be performed to eliminate the false positives anddistill them to a corrected set of domains. A configurable device 124within the network may detect an application's anchor domain and markthe source of the data and the time of detection. Following this time ofdetection, ongoing data flows from the same traffic source may be markedas belonging to the application that is associated with the anchordomain. The multi-tenant controller 122 may continue to receive dataregarding the traffic source from the configurable devices 124 andclassify the data flows, for example, into one of the following i)Applications B and C that might belong to Application A, ii) UnknownApplications without a known definition that might qualify as belongingto A, or iii) Applications D and E that might not qualify as belongingto A. The time-based cohesiveness of the data flows may be used tocluster traffic and data flows that appear to have a common underlyingSaaS or other application. This time-based cohesiveness may allowancillary data traffic to be detected and associated with theapplication, such as ad traffic that is presented within or inconjunction (e.g., interstitial ads) with an application.

In accordance with exemplary embodiments, such methods and systems fortime-based application domain classification and mapping may be appliedto application sessions as described above.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   detecting at a device an application having an anchor domain;    -   marking the application with a traffic source having an entry        point domain that accessed the application and a time of        detection; and    -   designating network flows from the traffic source within a        predetermined time from the time of detection as belonging to        the application.

A networked branch device configured to:

-   -   detect an application having an anchor domain;    -   mark the application with a traffic source having an entry point        domain that accessed the application and a time of detection;        and    -   designate network flows from the traffic source within a        predetermined time from the time of detection as belonging to        the application.

Any of the clauses above further comprising modeling applicationsessions and predicting bandwidth requirements.

Any of the clauses above further comprising performing anomalous sessionidentification, quarantine and restriction.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Planning for enterprise bandwidth requirements based on applicationusage, and developing associated policies for the handling of data flowsassociated with applications, can be difficult and inaccurate based atleast in part on the fact that the same application, within the sameenterprise, might be utilized in very different ways by the user groupswithin the enterprise. For example, the same application may havedifferent operational modes that create different data flow types. As asimple example, User Group 1 might use Application Z to download summaryfinancial reports, while User Group 2 might use Application Z to createthese reports. In this simplified example, User Group 2 is a heavieruser of Application Z in terms of time used, but also in terms of thenature and volume of the data flows that are associated with ApplicationZ. If such differences are not discovered and used as part of creatingapplication profiles, then such profiles can miscalculate the networkresources needed to run an application. When aggregated acrossapplications, the problem may be compounded and can lead to enterprisebandwidth estimates that are unreliable for predicting actual futurenetwork bandwidth requirements. In another example, personnel in a Salesand Marketing Dept. may have a different usage profile for the sameapplication than when the application is used by personnel from theEngineering Dept. Therefore there is a need for a process of identifyingusage differences the may assist in planning for bandwidth capacityneeds and making informed policy decisions, and modeling applicationsession(s) to determine network bandwidth, where application sessionsinclude transactional and bulk applications and those of mixed use, andusing data mining and other statistical techniques to predict networkrequirements and potential points of limited capacity that couldadversely impact data flows, or other network weaknesses. Such asolution may identify anomalies in the usage patterns and applynecessary checks, select appropriate WAN paths, and allocate appropriatebandwidth capacity (based on what an application requires).

According to the methods and systems of the present invention describedherein, statistical and data mining techniques may be applied fordynamic and on-going characterization of application usage, by session,for performance and predictive planning purposes may improve networkperformance. Big data-type analytic techniques may be used tocharacterize flows that are associated with application usage.Configured spoke devices may collect and send to the multi-tenantcontroller 122 such flow data. Analysis of this data may improve anadministrator's ability to summarize the resource needs of applicationsalong at least the following dimensions:

-   -   Bandwidth usage in both directions    -   Network response times    -   Application response times    -   Number of active and idle application sessions    -   Maximum number of concurrent application sessions

The results of analyzing the flow data may be reported to users, such asIT administrators of the network and provided to spoke devices in theform of traffic profile summaries. The spoke devices may in turn use thetraffic profiles to monitor bandwidth usage and application performance.Data sent to a spoke device may include, but is not limited to i)ingress and egress bandwidths determined based on analytics performed atthe controller, and ii) application response times. A spoke device mayuse this information to determine which one of the various availablepaths for an application is best suited to the application. Modeling andother analytic techniques, as described herein, may also be used tocharacterize data beyond flow data that are associated with applicationusage. Parameters used in modeling may include, but are not limited toapplication response time, ingress/egress bandwidth, server responsetime, transaction start and end times, size of transactions, or someother parameter.

Applications may broadly be classified into three categories:Transactional applications, bulk applications, and media applications.Transactional applications may be described by the size of thetransactions processed by an application, and the frequency oftransactions, which can be modeled and characterized. Data miningtechniques like centrality and classification may also be applied incombination to fine-tune the model. The resulting models may be betterable to predict the size and frequency of transactions for a typicalapplication session, as well as the frequency of application sessions.Bulk applications by nature consume any amount of bandwidth offered tothem for bulk data transfer and are often file transfer applications.These applications may also be modeled, but only to predict thefrequency of these application sessions. Applications that fall intoboth transactional and bulk categories may be modeled to identify thetransactional periods versus bulk periods of usage, and the frequency oftransactional and bulk transactions. Media applications are unique intheir own perspectives. These applications have the following types ofcharacteristics: a) sensitive to latency and jitter, b) may beunidirectional, 3) when bi-directional, will appear to be twounidirectional flows with different properties. These applications arefurther characterized by the type of codec negotiated and used on aunidirectional basis. Some example codecs used include, H.264, Mp4 forvideo, and G.711 and G.729 for audio. These codecs dictate how muchbandwidth is needed in each direction, and what the latency and jitterrequirements are.

In embodiments, the modeling and analytic methods used to characterizean application session and the corresponding network and bandwidthrequirements may also be used to monitor a network in real time forbandwidth requirements at the sub-channel level (transactional and bulkapplication types) and identify and predict trends in bandwidthrequirements. Because traffic flow characteristics associated with anapplication are not static, and a single data flow's characteristics maychange over the course of a session, accurate measurement andpredictions of application bandwidth needs may require real timemonitoring, such as that performed by a configurable device 124, asdescribed herein, to detect usage and bandwidth changes. For example,within a data flow for a single session of an application's usage,different behaviors may be monitored. For example, application behaviorsmoving from a transactional-type data flow to a bulk-type. Further,different human users 168 may cause an application session to have adifferent bandwidth profile. Application versioning may also impactbandwidth (i.e., recent upgrade may offer new features utilizingbandwidth differently than prior versions). Monitored data is sent fromconfigurable devices 124 to multi-tenant controller 122 for processing.

In order to develop an accurate application profile, a longer timewindow of an application session may better allow a multi-tenantcontroller 122 to detect the plurality of characteristics present thathave an impact on bandwidth and network resource requirements. Within asingle application session there may be a plurality of traffic typesdetected, such as: Transactional (e.g., human-to-human chat session overthe internet 142), real-time, bi-directional (e.g., a VoIP call (lowbandwidth); video call, like Skype (high bandwidth)), and/or bulktransfers (e.g., large file sharing applications). Traffic may bedirected over transmission control protocol (TCP) or user diagramprotocol (UDP) data flows. Bandwidth needs may be determined for anapplication and/or sub-application as a historical trend, usingstatistical models. Baseline application transaction times may becomputed in the context of each site, each application as a historicaltrend using statistical models. Packet loss, jitter, and MOS scores mayalso be computed for media applications as a historical trend usingstatistical models.

Based on application type detection, a multi-tenant controller 122 mayanalyze application session data that it receives from configurabledevice 124 at the branch 152 level to determine what amount of bandwidthis necessary for proper application performance. Application performancescores may be used to record and adjust the bandwidth profile for anapplication, where the profile states performance and bandwidth criterianeeded (i.e., a rule) for the type(s) of data flows detected duringapplication sessions. In an example, application traffic quality metric(ATQM) is one type of a performance score, and it is a measure of thetimes taken for completing application transactions. To measure theATQM, according to the methods and systems described herein, aconfigured device may track the requests and responses between client512 and server 160 (for transactional applications) and determine thetime taken, from a user's 168 perspective, for the full transaction tocomplete.

For transactional data flows, the peak-sustained bandwidth needed duringthe period of the transaction based on each direction may be determined.This determination may be based on historical monitoring measures. Thebandwidth may then be recorded in a traffic profile. For transactionalapplications, the size of the transactions and frequency of thetransactions may be modeled with various distributions like, normal,Weibull or a long tailed distribution, such as Pareto. Suchdistributions may be characterized using parameters, such as theaverage/peak bandwidth over short time intervals (e.g., few 100 s ofmsec to a couple of seconds), the frequency of transactions, and spatialand temporal localities identified, and/or data mining techniques likecentrality and classification may also be applied in combination tofine-tune the model. Such models may be used to predict the size andfrequency of the transactions for one application session and therebythe combination of ‘n’ number of sessions. In an example, at the startof a transaction, it may be determined that there is a need for 3 MB persecond based on the codecs being used. By peering into the sessionhandshake, the configurable device 124 may be able to determine, basedon the network traffic for example, which codec is used and at whatquality being negotiated. The configurable device 124 may use thisinformation to place data traffic on the appropriate data path, forexample, to avoid the placement of a bulk download on a high speed“lane.” Because malware is often performing data flows that areinappropriate for the data lane on which they occur, such identificationmay assist security implementations and analyses of suspect data flow.

Frequently in data networks, a single bulk data flow for an individualapplication can potentially consume all available bandwidth, but inpractice due to TCP behavior of client 512 and server 160, socketbuffers at either end and the bandwidth delay product (BDP) of the flow,there is a maximal bandwidth that can be less than the total linkcapacity. The monitoring information received by a multi-tenantcontroller 122 can be used to determine the range of minimum, average,and maximum bandwidth seen for an application flow based on data flowtype, and can compute and add to the traffic profile for theapplication. The multi-tenant controller 122 may recognize that atransactional flow has become a bulk flow and vice versa based at leastin part on the traffic classification profile, and applications may beclassified into categories based at least on the profiles developed.This may assist with appropriately categorizing applications with aplurality of functional capacities. For example, a single applicationmay enable chat and video conferencing, the first is transactional lowbandwidth and the second transactional, real time and high bandwidth.The user type may in part determine which aspect of the application ismore likely to be used, the time of day, or some other factor. Users 168of the applications can also be classified and incorporated into theapplication profiles (tellers v. loan officers, etc.). Once the spokedevices in a network have available to them the application profilesfrom the multi-tenant controller 122, they can better adapt to alteringdata traffic treatment and link capacity usage.

In accordance with exemplary embodiments, such methods and systems forapplication session modeling and prediction of bandwidth requirementsdescribed herein may be applied to application sessions as describedabove. Further, such methods and systems may utilize dynamic automatedQoS definitions as described herein.

In accordance with exemplary embodiments, the methods described hereinmay be applied to applications as described herein. Exemplaryembodiments may utilize file transfer applications as described herein.The methods and systems described herein may employ modeling andanalytics as described herein. Other exemplary embodiments may utilizeparameters for categorizing data flows as described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   receiving from a networked spoke device information describing        network flows to and from an application;    -   analyzing the information to characterize the application in at        least one dimension selected from the group consisting of        bi-directional bandwidth usage, network response times,        application response times, a number of idle and active        application sessions and a maximum number of concurrent        application sessions; and    -   transmitting the dimensions to at least one networked spoke        device as traffic profile information.

Any of the clauses above wherein the information describes L4 levelnetwork flows.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   receive from a networked spoke device information describing        network flows to and from an application;    -   analyze the information to characterize the application in at        least one dimension selected from the group consisting of        bi-directional bandwidth usage, network response times,        application response times, a number of idle and active        application sessions and a maximum number of concurrent        application sessions; and    -   transmit the dimensions to networked spoke devices as traffic        profile information.

Any of the clauses above wherein the information describes L4 levelnetwork flows.

A method comprising:

-   -   modeling a transactional application operating in a networked        environment by a size of transactions and a frequency of        transactions with a set distribution to produce one or more        modeled parameters; and    -   analyzing the modeled parameters to predict a data flow size and        frequency of one or more transactional application sessions.

Any of the clauses above wherein the set distribution is selected fromthe group consisting of normal, weibull and pareto.

A method comprising:

-   -   modeling a bulk application operating in a networked environment        by a size of transactions and a frequency of transactions with a        set distribution; and    -   analyzing the modeled parameters to predict the frequency of one        or more bulk application sessions.

Any of the clauses above wherein the set distribution is selected fromthe group consisting of normal, weibull and pareto.

A method comprising:

-   -   modeling an application operating in a networked environment by        a size of transactions and a frequency of transactions with a        set distribution to produce one or more modeled parameters;    -   detecting, based at least in part on the modeling, a hybrid        application traffic characteristic, wherein the hybrid        application traffic characteristic comprises a first data        traffic type that is correlated with at least one data traffic        characteristic of a transactional application and a second data        traffic type that is correlated with at least one data traffic        characteristic of a bulk application; and    -   analyzing the modeled parameters to predict a data flow size and        frequency of one or more hybrid application sessions.

Any of the clauses above wherein the set distribution is selected fromthe group consisting of normal, Weibull and Pareto.

A method comprising:

-   -   sending network usage data relating to an application usage        session from a configurable device to a multi-tenant controller,        wherein the network usage data comprises a first type of data        flow associated with an application and a second type of data        flow associated with the application;    -   identifying a bandwidth requirement for each of the first and        second types of data flows associated with the application        based, at least in part, on historical data relating to the        performance of the application and an associated data flow;    -   storing within the multi-tenant controller the bandwidth        requirement as an application bandwidth profile;    -   sending the application bandwidth profile to at least one spoke        device; and    -   using the application bandwidth profile to route data flows        associated with the application.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein routing is based, at least in part, ona dynamic and automated QoS definition.

Any of the clauses above wherein applications are selected from thegroup consisting of transactional applications and file transferapplications.

Any of the clauses above further comprising employing modeling andanalytics selected from the group consisting of Pareto and Weibull.

Any of the clauses above further utilizing parameters to categorize dataflows.

In traditional networks, the attribute indicating the amount ofbandwidth that is available is often specified manually and is oftenincorrect and/or out of date. This may negatively impact factors, suchas, routing, traffic engineering, and quality of service (QoS) controls.What is needed are mechanisms that utilize link bandwidth detection foractive and idle links that can be automated and updated in real time.Traditional networks often use QoS standardized controls at anindividual interface level to manage network performance, and todetermine such characteristics as prioritization of traffic flows. QoSstandardized controls include, but are not limited to, shaping,policing, random early discard (RED), weighted RED, tail drop, lowlatency queues, fair queues 818, and buffers attached to a plurality ofqueue types. These controls may be used to classify traffic and provide,for example, a weight-based allocation of bandwidth according to trafficclassification. In some embodiments, QoS may be defined in a dynamic andautomated manner by the system that does not require use input andoperates to adjust QoS to network conditions and requirements. However,enterprise needs are most often expressed in terms of businesspriorities that may differ from network priorities, and when inconflict, the traditional controls may give greater preference to anetwork priority over a business priority. For example, a real-time timeapplication may have lower business priority than a bulk application,however current technologies will still often give preference to thereal-time application over the bulk application.

Traditional networks may also not allow or facilitate dynamicallychanging the number of queues, buffers, schedulers and shapers 154,which are fixed. Thus, if new applications need to be added and theyneed a higher number of lower latency queues it will not be possible toserve those applications and achieve the needed performance. What isneeded are methods and systems for using business priorities that areexpressed as network policies that give preference to, and enforce,business priorities over network priorities, and that may scale bydynamically increasing or reducing QoS resources (e.g., queues, buffers,shapers 154, and schedulers) to ensure that business priority needs aremeet with changes in policies.

In traditional networks, hybrid applications having transactional andbulk functionalities and related data flows have varying levels ofbandwidth requirements that traditional networks are often poor atrecognizing and adjusting to accommodate for optimal applicationperformance. What is needed are methods and systems for identifying thecurrent functional capacity of an application (e.g., in a transactionalor bulk mode of operation), and adjusting the network bandwidthavailable to the application based at least in part on the current modeof operation of the application, and in accordance with a businesspolicy. Further, anomalous traffic detection is needed in order tocharacterize what is a typical application session's bandwidthrequirement for a given application and restrict usage of the bandwidththat is allocated to the application to what is a level appropriate toallow the application to properly function. Constraining the bandwidthmay be advantageous, for example, in preventing denial of service (DoS)attacks during which bandwidth needs will exceed the permitted bandwidththreshold specified by a policy.

Traditionally link capacity has been determined using a test-responsemeasurement and/or active-traffic based estimation. Test-response may beperformed when links are idle and typically happens at the “beginning”of a site's operation. Specific requests may be sent to servers 160hosted by an enterprise or a third party, and the available bandwidthmeasured. Active-traffic based estimation refers to a method by whichthe system estimates available bandwidth while there is active trafficgoing through the links. However, when active traffic is flowing throughthe links, test-response measurement can be disruptive and could yieldwrong results. Active-traffic based estimation relies on three keybehaviors of TCP connections between a client 512 and server 160: 1) ifthere is congestion anywhere on the path of the TCP connection, therewill be packet loss, 2) a client 512 that initiates a relativelylong-lived TCP connection that has more than just a few packetsexchanged in each direction, will attempt to continually increasing therate at which it transmits data. The server 160, if it sends lot ofdata, will do the same. For a very long-lived connection, the client 512and/or server 160 may use the entire link's capacity should networkconditions allow. And, 3) after performing behavior 2, above, if networkutilization has reached its limit, TCP connections will correctly settleon their share of the link before performing behavior 2 again.

Referring to FIG. 7, a configured device located within a network branch152 may employ a shaper 154 on every link connecting to a network 705 ineach direction (to and from). A shaper as the term is used herein may bea component of a configurable device or a component that is independentof a configurable device. A shaper 154 is a network artifact that limitsthe amount of data to a prescribed value. For example, if a shaper 154is set to 10 Mbps in one direction, it will not allow more than 10 Mbpsin that direction irrespective of how much is being attempted in thatdirection. If more than 10 Mbps is attempted to be sent, the shaper 154will drop packets to keep the rate at 10 Mbps. Congestion controlalgorithms (e.g., Reno and binary increase congestion control (BIC)) maybe used for bandwidth estimation. For idle links the estimation may beperformed in a manner that is similar to an Internet speed test. Foractive links, link capacity may be determined through continuousmonitoring and correction. In an example, links may have an ingress andegress shaper 154, as described herein, that controls how much trafficcan be put on the link or received from the link. Any traffic exceedingthe shaper's 154 limits may be dropped. A shaper's limit may be set bybandwidth estimation logic. At the start, this limit may be set to‘unlimited’ or a very large value. Bandwidth estimation may periodicallyconsider two inputs for every shaper 154: (a) count of dropped packetsat the shaper 154 [DROP-SH] (b) count of dropped packets due tocongestion on the collection of flows on the link [DROP-CNG]. Bandwidthestimation logic may “hunt” for proper link capacity as depicted in FIG.8A. If no DROP-CNG, but DROP-SH is detected at the shaper 154 for twoconsecutive minutes, the result, in one example, may be to increaselink-bandwidth by 5%. In another example, if DROP-CNG is detected for 2consecutive minutes, the link-bandwidth may be set at 95% of currentlink bandwidth (one exception to this may be in a startup/initializationphase, where the link-bandwidth=80% of the current link-bandwidth toallow for faster convergence). In another example, if nothing isdetected for more than two hours, the link-bandwidth may be increased by5%.

According the methods and systems, as described herein, these drops maybe detected and if these drops are present over a period of time (e.g.,120 seconds) the system may declare that it has detected actionabledrops at the shaper 154 (DROP-SH). The configured device at the branch152 may also monitor packet retransmits that might occur on TCPconnections. Packet retransmits may indicate packet loss (hence it isgetting retransmitted). However, packet loss may happen due to manyconditions, some of which are not due to general network congestion. Forexample, TCP connections to a specific server 160 in Kansas might seepacket retransmits but others do not. This very likely is due to aserver 160 or network issue close to the server 160 in Kansas. To avoidfalse positives, the system and methods described herein may monitorpacket retransmits across all connections holistically, assess thenumber of applications seeing packet retransmits, and perform suchoperations over a moving time window of, in one hypothetical example,180 seconds, processed every 10 seconds. Thus, the time window of 180seconds moves to the “right” every 10 seconds by 10 seconds. In anotherexample, if twelve such consecutive measurements indicate that, forexample, more than two-thirds of currently active applications at thatdevice are seeing packet retransmits, then the system may declare thatit has detected actionable congestion in the network 528 on that link.Such congestion caused packet loss (DROP-CNG) may cause packetretransmits. With DROP-SH and DROP-CNG, the system may, for example,perform the following:

Hunting DROP- State DROP-SH CNG Inference Action Init 802 Present AbsentShaper 154 is too Increase shaper restrictive and 154 limit by 5%. therecould be Go to Hunting more capacity on state the link Don't carePresent Network is Decrease shaper seeing 154 limit to 80% congestion ofcurrent value. Go to Hunting state Hunting Absent Absent If this Go toStable 808 combination state persists for 5 minutes, we have achievedSTABLE 808 condition Present Absent Shaper 154 is too Increase shaperrestrictive and 154 limit by 5% there could be more capacity on the linkAbsent Present Network is Decrease shaper seeing 154 limit to 95%congestion of current value Present Present Network is Decrease shaperseeing 154 limit to 95% congestion of current value Absent Absent Ifthis Go to Stable combination state persists for 5 minutes, after havingadjusted shaper 154 limit, we have achieved STABLE 808 condition Stable808 Absent Absent If this Increase shaper combination 154 limit by 5%persists for 2 Go to Hunting hours in the state presence of nearcapacity link usage, time to see if more capacity is available innetwork Present Absent Shaper 154 is too Increase shaper restrictive and154 limit by 5%. there could be Go to Hunting more capacity on state thelink Don't care Present Network is Decrease shaper seeing 154 limit to95% congestion of current value. Go to Hunting state

If there is no congestion in the network and there is demand for moreutilization as seen by the drops at the shaper 154, then an attempt toincrease link capacity may be performed by easing the shaper 154 limit.If there is congestion in the network, then a decrease in the rate ofdata pushed on the link may be implemented by decreasing the shaper 154limit. The result may be for each TCP connection to adjust to the newsettings and, after a set period of time, settle on the new availablecapacity at the shaper 154.

According to the methods and systems of the present invention describedherein, shapers 154 may be added or deleted based on the level ofbusiness priority associated with the traffic. This may be performeddynamically, for example, based on application demand, where the dynamicperformance is carried out in compliance with a policy maintained at amulti-tenant controller 122. Performance-based routing may beaccomplished by estimating link capacity automatically and dynamically,in near-real-time.

Network traffic may be classified based at least in part on a businesspriority, and bandwidth allocation to a plurality of applicationsrunning on a network may be determined based at least in part onassigned business priorities. A network administrator may createmultiple business priority classes and assign each a priority orderand/or ranking. In an example, a lower number for priority order may beconsidered a higher priority. For example, an administrator may create 4classes “Platinum”, “Gold”, “Silver” and “Bronze” and give them priorityorder 10, 20, 30 and 40. Important applications like Office365 may get aPlatinum, high-priority ranking, whereas recreational applications, suchas YouTube, may be ranked lowest priority. An administrator may alsoprovide a percent-allocation of bandwidth between the priority classes(e.g., 50% to Platinum, 30% to Gold, and so forth). A configured devicemay first detect the network type of each application data flow, forexample, real-time, bulk or transactional. The configured device maycreate multiple queues for each business priority (e.g., strict priority814, fair 818 and anomaly 820). A strict priority queue 814, forexample, may be a queue for sending latency sensitive real time traffic(e.g. voice). If traffic is present in the queue it may be servicedbefore other queues (e.g., fair 818 or anomaly 820) are serviced. Fairpriority 818 queue examples include, but are not limited to, queues thatcarry transactional or bulk traffic, such as web applications, or filedownload. These queues may be found in round robin fashion along withthe anomaly queues 820. Anomaly 820 queues are queues that carry trafficfor applications showing anomalous bandwidth consumption behavior (e.g.,a chat application that rarely consumes more than 10 Kbps startsconsuming 5× its regular consumption). An anomalous queue 820 may beused for those flows that are to exceed their traffic profile basedbandwidth by a large margin. A shaper 154 may be used in front of theanomaly queues 820 to ensure that the anomaly flows do not impactbandwidth available for other flows. Anomaly queues may have a shaper154 that restricts maximum bandwidth allowed to such anomalous behavingapplications. The number of queues and the amount of buffering for eachmay be based on a formula that uses the current number of data flows andtheir network types. Fair queues 818 may be split into fair queues 818for transactional traffic v. bulk traffic.

In embodiments, real-time traffic flows may be assigned to real-timequeues, transaction flows to transactional fair queues and bulk flows tobulk fair queues 818 and directed by a multi-tenant controller 122, asdescribed herein. A flow that changes from transaction to bulk and viceversa may be dynamically moved to the right queue. A configured devicemay use a shaper 154 per business priority class. This configured shaper154 may be set to the sum of the total estimated bandwidth acrossapplication flows that are currently queues against the strict 814, fair818 and anomaly 820 queues. This configured shaper 154 may be used ifthe administrator has given a percentage bandwidth allocation across thebusiness priority classes. The administrator can add or delete abusiness priority class dynamically. This, in turn, may be used todynamically add or delete business priority shapers 154 and queues. Abusiness priority scheduler may “drain” traffic. As used in thiscontext, “drain” refers to removing a packet sitting in a queue andsending it out of an interface from the queues across queues of aplurality of business priorities classes. The scheduler may use analgorithm that uses a combination of business priority and network typeof the queues to decide how to drain them. This algorithm may ensurethat if the interface has sufficient bandwidth then a lower businesspriority traffic having real time network type will continue to havesatisfactory performance while not impacting the performance ofreal-time, bulk or transaction application flows belonging to a higherbusiness priority class. If sufficient bandwidth is not available forboth business classes, then the business priority scheduler algorithmmay give preference to flows of higher business priority. The algorithmmay use a similar method when there is more than one business priorityclass.

In embodiments, and referring to FIG. 8B, the bandwidth that isconsidered sufficient for a business priority class may be the sum ofreal-time flow bandwidth amounts, sustained peak bandwidth fortransactional flows and minimal sustained bandwidth of bulk flows. Thisinformation may be presented in the traffic profile of an application.Within a business priority class, real-time flows may be given a higherpriority, followed by transactional flows, followed by bulk flows. Thepriority between transactional and bulk may not be strict 814 but mayinstead be weight-based with a higher weight provided for transactionflows but non-zero weight for bulk flows. Real-time flows however mayhave strict 814 priority and get drained first. An algorithm may takeinto consideration the dynamically changing link bandwidth of Internetlinks and also the percentage allocation specification set by anadministrator between business classes. The dynamic, algorithmicmonitoring may be used bidirectionally for each WAN interface. It may beapplied against the egress direction on WAN interface for WAN trafficgoing towards WAN. It may also be applied against egress directiontowards LAN for WAN traffic that is coming from WAN, and the configureddevice may be able to monitor the bandwidth usage in a passive mannerand without introducing additional data traffic in order to test thebandwidth (i.e., the configured device is not adding to congestion).

In embodiments, configured spoke devices may adjust the bandwidth queuesat reasonable or set time periods to ensure that the bandwidth offeredto all sessions of an application matches the need of the applicationsessions, while honoring the business priorities. For example, if thereare 10 sessions of a P1 application, and each session needs 10 Kbps,then the bandwidth queues may be adjusted such that 100 Kbps is offeredto that application, assuming bandwidth is available for the rest of theP1 applications, and the total share of bandwidth used by all P1applications doesn't exceed a certain percentage. If the number ofsessions of the same application increased to 50, then the bandwidthqueues may be adjusted such that 500 Kbps is offered to thatapplication, while still meeting the other constraints. Configureddevices may detect anomalous application sessions depending on theamount of bandwidth consumed, and may move those sessions to ananomalous queue 820, where the bandwidth offered to such applicationssessions is restricted.

In accordance with exemplary embodiments, such methods and systems foranomalous application session identification, quarantine and restrictiondescribed herein may be applied to application sessions as describedabove. Further, such methods and systems may utilize dynamic automatedQoS definitions as described herein. The methods and systems describedherein may employ modeling and analytics and use QoS standardizedcontrols as described herein. Other exemplary embodiments may utilizeparameters for categorizing data flows as described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   issuing a tuned request on a specified active link having an        ingress shaper and an egress shaper to a server utilizing a link        capacity to an extent in both a forward path and a return path;    -   determining a link capacity for the active link;    -   monitoring the active link; and    -   dropping any traffic traveling via the active link when a limit        of at least one of the ingress shaper and the egress shaper is        exceeded.

A method comprising:

-   -   issuing a request on a specified active link having an ingress        shaper and an egress shaper to a server utilizing a link        capacity to an extent in both a forward path and a return path;    -   determining a link capacity for the active link;    -   monitoring the active link;    -   determining a limit of the ingress shaper and the egress shaper        based, at least in part, using bandwidth estimation logic; and    -   dropping any traffic traveling via the active link when the        limit is exceeded.

A method comprising:

-   -   receiving a plurality of business priority classes;    -   detecting a network type associated with each of a plurality of        application data flows in a network wherein the network data        flow types are selected form the group consisting of real-time,        bulk and transactional;    -   creating a plurality of strict priority queues, fair queues and        anomaly queues for each of the plurality of business priority        classes; and    -   assigning real-time network data flows to real-time queues,        transactional flows to fair queues and bulk flows to bulk fair        queues.

A method comprising:

-   -   monitoring a bandwidth of an application comprising an        application session at a configured spoke device at a        predetermined time interval; and    -   adjusting the bandwidth such that the bandwidth matches a        requirement of the application session while meeting the        requirements of one or more defined business priorities.

Any of the clauses above further employing a multi-tenant controllerbased mapping of a user or device identity to a network level identity.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein routing is based, at least in part, ona dynamic and automated QoS definition.

Any of the clauses above further comprising employing modeling andanalytics selected from the group consisting of Pareto and Weibull.

Any of the clauses above further comprising employing QoS standardizedcontrols selected from the group consisting of shaping, policing, randomearly discard, tail drop, low latency queues, fair queues, anomalyqueues and buffers.

Any of the clauses above further utilizing parameters to categorize dataflows.

Traditionally network traffic engineering is based on destination IPaddresses and/or a source IP address, but not on higher-level user ordevice identity. The creation of usage-based policy may allow anenterprise to enforce network policy using the identity of a user 168that is accessing an application. For example, Active Directory (AD) 904may be used as a source of user 168 and group identity information. Whatis needed are methods and systems for enforcing a user 168 or user-basedpolicy by mapping IP-to-user-events 912, 914 to a spoke site, where suchevents derive from multiple elements which may be present in multipleother sites, and enforcing policy at the network level usinghigher-level identity an administrator needs to map higher-level user168 and/or device identity to network level identity. Network levelidentity as used herein may be terms of L2 (MAC Address, VLAN Tag)and/or L3 identity (IP Address) and/or L4 Identity (e.g. TCP portnumber, UDP port number).

According to the methods and systems of the present invention describedherein, a central multi-tenant controller 122 may be used to collect theidentity information relating to users 168 of an application running ona network, and use a horizontally scalable algorithm to keep track ofchanging identity information so that the multi-tenant controller 122can keep a policy updated so that it can enforce user 168 based networkpolicy and provide accurate user 168 based networking and applicationmonitoring data. In embodiments, a multi-tenant controller 122 may beused to collect the IP-to-user mapping events 912, 914 and may use ahorizontally scalable algorithm within the multi-tenant controller 122to decide which spoke site needs an event. Based on this information,the multi-tenant controller 122 may then distribute the mapping to thespoke device in the correct spoke site. A spoke device may use theIP-to-user mappings 912, 914 to identify which user 168 or user group aparticular application flow belongs. It may then enforce a user-, oruser group-based policy on that data flow. Spoke devices and hub devicessupport roles, including but not limited to discovery of AD using DNS[DNS ROLE], and tracking changes in user 168 and group identities usinglightweight directory access protocol (LDAP) communication with AD [LDAPROLE].

In embodiments, a multi-tenant controller 122 may run horizontallyscalable services called Identity Management (IDM) Services 902. For agiven tenant, the multi-tenant controller 122 IDM service may select aset of elements and instruct them to run DNS ROLE and discover all ADdomains and list the AD servers in the enterprise. The DNS ROLE maycontinuously monitor additions and deletions of AD domains,addition/deletions of AD server, and changes in IP address of ADservers. The DNS ROLE may keep the multi-tenant controller 122 IDMservice informed of these changes and the IDM service 902. Themulti-tenant controller 122 may present the list of AD domains and ADservers to the tenant administrator and request credentials tocommunicate with the AD servers using LDAP and Windows ManagementInstrumentation (WMI). WMI is a communication protocol supported byMicrosoft AD Servers. Devices external to Windows AD servers can usethis protocol to communicate with Windows AD server and obtaininformation on events (including login and logout events) on the WindowsAD server. For each AD domain, the multi-tenant controller 122 IDMservice may select an element at a hub site that will run LDAP ROLE tocommunicate using LDAP with one or more AD servers for the AD domain.The multi-tenant controller 122 may use a specific algorithm to decidewhich hub site is the optimal hub site whose elements should run theLDAP ROLE and also determine if there are multiple elements in the hubsite elements communicating with the AD servers and which AD servers areinvolved. The algorithm may minimize load on the AD servers, achievefair load distribution across hub device elements, and contain LDAPcommunication to LAN rather than WAN. The element running LDAP ROLE mayderive basic information such as full name, AD numerical ID, AD stringID for users 168 and groups, or some other type of identifyinginformation. It may do this for those users 168 and user groups that themulti-tenant controller 122 wants to track for the purpose of enforcinga policy (e.g., the user 168 or user group is used in a policy'sidentity field) and for the purpose of monitoring and troubleshooting(e.g., the user 168 is present in a spoke site with a configurableelement).

In embodiments, a multi-tenant controller 122 may make available anexisting user 168 or user group identity to an IT administrator so thatthe administrator can use them in a policy. The multi-tenant controller122 may generate a separate controller-based ID for each AD identity andfurther keep a mapping of its ID in AD. The multi-tenant controller 122may send a policy to each element and, in lieu of the AD identity, senddown the ID it has locally generated. This ID may then be used by eachelement to enforce policy. The multi-tenant controller 122 IDM service902 may also make available the information of the AD to a statisticsand analytics service so that it can display full user name and ADinformation about the user 168 for the purpose of reporting andmonitoring. The benefits of these methods and systems of identity-basedpolicy may include, but are not limited to, 1) the use of user identityin policy may improve WAN traffic engineering for performance andcompliance, 2) the multi-tenant controller 122 may optimize mapping ofelement-to-AD preferred communication paths for the purpose ofmonitoring user/group identity additions, deletions and changes (themulti-tenant controller 122 may accomplish this at scale across hundredsof AD sources and hundreds of elements per enterprise and acrossthousands such enterprises), and 3) the multi-tenant controller 122'suse of algorithms may allow for a horizontally scalable controllerservice and that specifically minimizes LDAP traffic on WAN. Eachconfigurable element may support a role for tracking of security loginevents using Windows management instrumentation (WMI) communication withAD [WMI ROLE]. The security login events may include informationrelating to user name and IP address.

In embodiments, a multi-tenant controller 122 may run a horizontallyscalable service IP to Site Mapping (ISM) Service 903. For a giventenant, the multi-tenant controller 122 IDM Service may select a set ofelements and instruct them to run DNS ROLE and discover all AD domainsand list of AD servers in the enterprise. The DNS ROLE may continuouslymonitor additions and deletions of AD domains, addition/deletions of ADservers and changes in IP address of AD servers, and keep the controllerIDM service 902 informed of these changes and the IDM service 902. Themulti-tenant controller 122 may present the list of AD domains and ADservers to the tenant administrator and request credentials tocommunicate with the AD server's WMI. The multi-tenant controller 122may run an algorithm to decide which element (from all the spoke and hubelements) will run the WMI ROLE that will contact specific AD instances.The algorithm may use information about subnets/prefix served by eachAD, the local and discovered prefix sites of a site, and select a spokeor hub element to run WMI role so that it can get the necessary securitylogin events. The algorithm may identify the correct AD, contain WMIcommunication to LAN and minimize it over WAN and take care of failuresof the AD.

In embodiments, the configurable elements running WMI roles using WMIwith AD may receive specific AD login security events indicating the IPand AD user string ID and AD user numerical ID, and send a IP-to-usermapping events 912, 914 to the multi-tenant controller 122's IP-to-SiteMapping (ISM) service 903. In an example, a WMI Role on a configurableelement may receive an AD security event (login event) from AD usingWMI. This event may include the IP address and AD ID and name of theuser 168 who has logged into AD. The WMI Role may then form a messageusing this information, and this message may be called as an IP-to-usermapping, and send the message to the multi-tenant controller 122's ISMservice 903. The ISM service 903 may run an algorithm that builds adata-based lookup method that uses the local and discovered prefix sets915 of sites and the IP address in the IP-to-user mapping event 912, 914to find to generate a IP-to-Site mapping 916. It uses this IP-to-Sitemapping 916 to decide which spoke site a given IP-to-user mapping event912, 914 should be sent. The ISM 903 may change the AD user ID to amulti-tenant controller 122 user ID (which matches the user ID in apolicy of interest) in the IP-to-user mapping event 912, 914. It mayalso add group ID's to the event for all groups to which the userbelongs. The ISM 903 may send the enriched IP-to-user mapping event 912,914 to the correct spoke site and also record this IP as belonging tothe user in the multi-tenant controller 122 database. Each databaseentry may have a validity period of 30 days (or some other timeframe)after which the entry is purged.

In embodiments, spoke elements may use the IP-to-user event 912,914obtained from the ISM 903 service to build an IP-to-userID andIP-to-groupID cache. For each incoming application flow, this cache maybe used to determine the user 168 and group ID for the flow and use thisID to lookup policy and enforce policy. When the spoke elements generateflow statistics for the flow they may include the user 168 and groupID's as part of the flow statistic record and send it to a multi-tenantcontroller statistics service. The multi-tenant controller statisticsand analytics service may store the statistical records with the user168 and group ID information, and provide monitoring and troubleshootinginformation for a particular user 168 or group. The multi-tenantcontroller 122 may collect all the IP-to-user events 912, 914 frommultiple elements and map them to the final site having an element thatneeds to consume that event for enforcing policy on the data path. Themulti-tenant controller 122 may map which element should communicatewith which AD as IP-to-user event source. The multi-tenant controller122 may scale across hundreds of AD sources and hundreds of elements perenterprise and across thousands such enterprises. The use of algorithmsmay allow for a horizontally scalable multi-tenant controller servicethat eliminates WMI traffic on WAN and reduces the amount of IP-to-usermapping traffic on WAN.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   executing at a controller a horizontally scalable service        Identity Definitions Manager (IDM) Service;    -   mapping active directory (AD) domains to WAN network elements        DNS ROLE and LDAP ROLE;    -   instructing a plurality of network elements associated with a        tenant to discover a plurality of AD domains and AD servers in        an enterprise using the DNS ROLE;    -   receiving from the plurality of network elements running DNS        ROLE information indicative of changes to network attributes        selected from the group consisting of AD domains, additions and        subtractions of AD servers and changes in an IP address of AD        servers;    -   transmitting the received AD domains and AD servers to a tenant        administrator and requesting credentials to communicate with        added AD servers using LDAP; and    -   executing an algorithm to determine which element will contact        specific AD instances to minimize lightweight directory access        protocol (LDAP) traffic volume occurring on the WAN and to        ensure AD instances can still be reached in case of failure of        any one network element;    -   monitoring in Active Directory servers changes in at least one        identity (user or group) of a network user by using the LDAP        ROLE on the network elements; and    -   updating a policy, based at least in part on the mapping of user        identity in AD domains, at a multi-tenant controller, wherein        the tracking of changing identity information is implemented as        a horizontally scalable service the Identity Definitions Manager        Service

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

running at a controller a horizontally scalable service IdentityDefinitions Manager (IDM) Service;

-   -   mapping active directory (AD) domains to WAN network elements        DNS ROLE and LDAP ROLE;    -   instructing a plurality of network elements associated with a        tenant to discover a plurality of AD domains and AD servers in        an enterprise using the DNS ROLE;    -   receiving from the plurality of network elements running DNS        ROLE information indicative of changes to network attributes        selected from the group consisting of AD domains, additions and        subtractions of AD servers and changes in an IP address of AD        servers;    -   transmitting the received AD domains and AD servers to a tenant        administrator and requesting credentials to communicate with        added AD servers using LDAP; and    -   executing an algorithm to determine which element will contact        specific AD instances to minimize lightweight directory access        protocol (LDAP) traffic volume occurring on the WAN and to        ensure AD instances can still be reached in case of failure of        any one network element;    -   receiving from the LDAP ROLE of network element changes in        Active Directory servers in at least one identity (user or        group) of a network; and    -   updating a policy, based at least in part on the mapping of user        identity in AD domains, at a multi-tenant controller, wherein        the tracking of changing identity information is implemented as        a horizontally scalable service the Identity Definitions Manager        Service

A network element executing DNS ROLE and LDAP ROLE configured to:

-   -   obtain instructions from a central multi-tenant controller IDM        server on which domains to discover AD servers in using DNS role    -   Discovering using DNS ROLE information indicative of changes to        network attributes selected from the group consisting of AD        domains, additions and subtractions of AD servers and changes in        an IP address of AD servers, and transmitting this information        to the multi-tenant controller IDM service;    -   receiving from the multi-tenant controller IDM service the        credentials to communicate with discovered AD servers using        LDAP; and    -   monitoring in Active Directory servers changes in at least one        identity (user or group) of a network user by using the LDAP        ROLE on the network elements and transmitting these changes to        the multi-tenant controller IDM service.

A method comprising:

-   -   executing at a controller a horizontally scalable service IP to        Site Mapping (ISM) Service;    -   instructing a plurality of network elements associated with a        tenant to discover a plurality of AD domains and AD servers in        an enterprise;    -   receiving from the plurality of network elements information        indicative of changes to network attributes selected from the        group consisting of AD domains, additions and subtractions of AD        servers and changes in an IP address of AD servers;    -   transmitting the received AD domains and AD servers to a tenant        administrator and requesting credentials to communicate with        added AD servers using WMI;    -   executing an algorithm to determine which element will contact        specific AD instances in order to contain WMI communication over        LAN and minimize WMI communication over WAN;    -   monitoring, using the WMI role on the network elements, the AD        servers security login events comprising an IP address, a user        AD ID and a user name;    -   converting the login events to IP-to-user events and        transmitting these to the ISM service in the controller;    -   using the ISM service to map these IP-to-user events to the        right spoke site;    -   sending the events with enriched information comprising one or        more group IDs for the user to the element in the spoke site;        and    -   using the enriched IP to user event at the spoke site to enforce        policy based on user and group IDs and to enrich flow and        application statistics with user and group information.

A centrally controllable multi-tenant controller for controlling aplurality of assets across a plurality of distributed computingenvironments wherein the controller is configured to:

-   -   execute at a controller a horizontally scalable service IP to        Site Mapping (ISM) Service;    -   instruct a plurality of network elements associated with a        tenant to discover a plurality of AD domains and AD servers in        an enterprise;    -   transmitting the received AD domains and AD servers to a tenant        administrator and requesting credentials to communicate with        added AD servers using WMI; transmitting the credentials to the        network elements running WMI ROLE;    -   executing an algorithm to determine which element will contact        specific AD instances in order to contain WMI communication over        LAN and minimize WMI communication over WAN;    -   receiving from the elements a plurality of AD server login        events which contain user IP address, user AD ID and user name;    -   converting these login events to IP-to-user events and        transmitting these to the ISM service in the controller.    -   using the ISM service to map these IP-to-user events to the        right spoke site;    -   sending these events with enriched information comprising a        group ID for the user to the element in the spoke site; and    -   using the enriched IP to user event at the spoke site to enforce        policy based on user and group IDs and to enrich flow and        application statistics with user and group information.

A method comprising:

-   -   obtaining instructions from a central multi-tenant controller's        IDM service to discover a plurality of AD domains and AD servers        in an enterprise using DNS ROLE;    -   transmitting information to a multi-tenant controller IDM        indicative of changes to network attributes selected from the        group consisting of AD domains, additions and subtractions of AD        servers and changes in an IP address of AD servers;    -   receiving credentials from the multi-tenant controller to        communicate with added AD servers using WMI;    -   monitoring, using the WMI role, the AD servers security login        events comprising an IP address, a user AD ID and a user name;        and    -   converting the login events to IP-to-user events and        transmitting the login events to an ISM service in a controller.

A method comprising:

-   -   receiving enriched IP to user event at a spoke site from a        multi-tenant controller's IP to Site Mapping Service to enforce        policy based, at least in part, on a user and a group ID; and    -   enriching flow statistics and application statistic with user        and group information.

Any of the clauses above further utilizing a network identity type.

With traditional networks, changes to the network may comprise a majorevent. Typically, effort is made to implement planned changes duringplanned “outage” windows. Further, changes are often made blindlywherein personnel ‘pray’ for things to be acceptable. Regardless, suchchanges are necessary. For example, a new application needs to be rolledout and the network has to be adjusted to allow, accommodate, controland route the application's traffic.

Change planning and execution in a network is more art than science dueto (1) the complexity of the network, (2) the lack of end-end view andcontrol of the network and (3) the lack of understanding of theapplication's needs and demands.

Such network planning is not new. However, such planning is typicallybeyond the capabilities of the network management tools that manage thedevices in the network. Such planning is typically performed inisolation from the real network and is complex, works with stale dataand requires translation from a planned view to effecting the changes inthe network.

In accordance with exemplary and non-limiting embodiments, there isprovided a multi-tenant controller 122 to centrally view and control thenetwork topology, configurable device 124 in the topology and theapplication of policies to solve the operational needs of networkadministration. A multi-tenant controller 122 may be used to identifyand map the topology of a network and use the network view to determineoptimal policy and device usage of network assets.

As described more fully herein, there is implemented a three partsolution. First, the network 528 is simplified from a user interactionperspective and there are no routing protocols and routing translationsto configure. Second, an end-end view of the controlled network 528 isalways available. Lastly, the described solution is built, in part, onan understanding of the applications and thus enabling the network foran application is a native capability.

In accordance with exemplary embodiments, the multi-tenant controllerrecords data indicative of where all devices and applications arelocated. As described more fully below, this provides for globalknowledge and allows for the provision of what-if scenarios. As aresult, a customer may query the multi-tenant controller 122 directly tosee which devices and applications are resident on the network 704.

For example, a network 528 supports 450 sites and wishes to add a451^(st) site. How will this change affect routing topology and flow oftraffic packages? In accordance with exemplary embodiments, when a newsite is added, the changes to the network topology are updated at themulti-tenant controller 122. Because the multi-tenant controller 122 hasaccess to the HTTP flow, the multi-tenant controller 122 may be queriedto, for example, show all paths between sites and simulate networkfunction. The multi-tenant controller 122 may have access to bandwidthand links in its topology graph of the network. Utilization of each linkcan also be gathered and stored for access by the multi-tenantcontroller 122.

In accordance with exemplary and non-limiting embodiments, themulti-tenant controller 122 may simulate the effects of changes to anetwork 528. The multi-tenant controller 122 may keep track of allconfigurations (devices, interfaces, capacities, policies and more) forall the devices in the network 528. Configuration management may be inreal or near-real time to ensure minimal data latency.

The multi-tenant controller 122 may also keep large amounts ofmonitoring data on traffic types, traffic load and applicationstatistics. The multi-tenant controller 122 may also allow for thecreation of ‘empty’ or hypothetical sites, specifically, ones that arenot real but are, for example, being planned.

In an exemplary embodiment, the effect of adding a new ‘site’ or deviceto the network 528 may be simulated through the multi-tenant controller122 with the ability to view projected traffic flow, capacity needs onlinks and DC devices, and business impact through traffic offload fromtraditional high cost network connectivity.

In accordance with such embodiments, the network administrator mayprovide (a) the type of site, (b) planned connectivity to the site, (c)planned policies for the site, and (d) an anticipated number of endusers 168 at the site. As used herein, the type of site refers,generally, to a spoke (remote branch 152), hub (data center 128) orservice (where certain network services exist but these sites are unlikea traditional DC or branch 152).

Using these inputs and the additional data to which the multi-tenantcontroller 122 has access from the network 528, the multi-tenantcontroller 122 may provide an integrated view of the new planned siteplus all the existing sites already in the network 528 as well as assessthe routing effects, traffic flow effects and the policy effects of thenew planned site as if it were already in the network 528.

To estimate an impact on applications and their traffic, themulti-tenant controller 122 may use any available existing statisticsand monitoring data collected from similar sites in the customer'snetwork already controlled and managed.

Examples of such data include, but are not limited to, (1) the type andnature of applications, (2) the number of users 168 or other datainstead of users 168 such as, for example, the number of flows/sec,total simultaneous application sessions and flows, (3) the peak andaverage amount of data entering and exiting such a site and periodicityof such metric, (4) the measured application performance, networkconnectivity latencies and packet losses seen by applications from asite with geographical and connectivity similarity and (5) theconfigured and measured available bandwidth on links/connectivity,diurnal or other periodic variables on available bandwidth on such linksfrom similar providers (since a customer typically involves the sameprovider across many sites).

As described more fully below, application profiles are accessible basedon information collected from various types of sites. Applicationprofile includes bandwidth, latency and jitter requirements. Inaddition, there may be stored and accessible user (group) profiles basedon information collected from various sites. User profiles may includeinformation such as (a) which applications does a typical user 168belonging to a group consume and (b) what are the typical times at whicha user 168 accesses which applications. Using this information, one mayestimate what the connectivity needs will be for a new site if theadministrator can tell what type of user (groups) are going to be at thesite, and how many of them there are likely to be and the like.

The effect of adding or changing a policy in the network can besimulated using the multi-tenant controller 122 with the ability to viewprojected traffic flow, capacity needs on links and DC devices, andbusiness impact through traffic offload from traditional high costnetwork connectivity. When a policy is planned to be added or changed,the network administrator provides (a) the policy to be added/changedand (b) the sites that he/she intends to apply the change to. With theseinputs and the additional data the multi-tenant controller 122 has fromthe network 528, the multi-tenant controller 122 may provide anintegrated view of the new policy plus all the existing policies and thesites they apply to and assess the routing effects and traffic floweffects as if it were already in the network 528.

To estimate the impact on applications and their traffic, themulti-tenant controller 122 may use any available existing statisticsand monitoring data collected from similar sites in the customer'snetwork already controlled and managed. In addition to the statisticsdescribed above, the multi-tenant controller 122 may further consider anestimate of how moving flows away from or to a link or destination freesup, congests the links and removes or adds to the load at a site. Forexample, if traffic to office365.com is going through a DC and then tothe Internet 142, adding a site with a policy to directly send suchtraffic to office365.com without sending it via the DC may illustratehow load and congestion on the links at the DC can be altered.

In accordance with other exemplary embodiments, the effect of adding newbandwidth/capacity with additional network connectivity (like a newInternet link) can be simulated through the multi-tenant controller 122with the ability to view projected traffic flow, capacity needs at DCdevices, and business impact through traffic offload from traditionalhigh cost network connectivity. When a new link or network capacity isplanned to be added to a site or set of sites, the network adminprovides (a) the site and (b) the network links that will be added tothe site. With these inputs and the additional data it has from thenetwork 528, the multi-tenant controller 122 may provide an integratedview of the new planned network connectivity plus all the existing linksalready available at the site and assess the routing effects, trafficflow effects and the policy effects of the new planned networkconnectivity as if it were already at the site.

To estimate impact on applications and their traffic, the multi-tenantcontroller 122 may use any available existing statistics and monitoringdata collected from similar sites in the customer's network alreadycontrolled and managed.

As described herein with reference to various exemplary embodiments,estimation may be performed to predict the impact of network changes onapplications and related network traffic. In all of these embodiments,various inputs may be utilized. For example, a first input that may beutilized includes the topology of a network. As described elsewhereherein, the topology may be synthesized at the multi-tenant controller122. The topology of a network may provide a tree-graph representationof configurable devices 124, connectivity through MPLS 144 (PrivateWAN), Internet 142 (Public WAN) and IPSEC based VPN methods over PrivateWAN and Public WAN. The multi-tenant controller 122 may also discernreachability to other parts of network (where configurable devices 124may not exist) based on information exported from the configurabledevice 124 at the branch.

A second input may comprise a type of network, e.g., Private WAN, PublicWAN, Internet VPN and Private VPN.

A third input may comprise application definitions—both system-providedand customer-defined—maintained at the multi-tenant controller 122.Identity/User definitions described elsewhere herein may be part ofdefinitions used in policies. User/Identity definitions may be receivedand processed and interpreted at the multi-tenant controller 122 asspecified elsewhere herein.

A fourth input may comprise policies that prescribe which application isallowed to use which type of connectivity at a specific site.

A fifth input may comprise monitoring data (telemetry) from existingactive sites or sites in monitor mode on some or all applications. Thetelemetry from each site for every application may include thefollowing: (a) bandwidth consumed over time over every network typeincluding average and peak data, (b) data transferred over time overevery network type, (c) number of simultaneous flows over time and (d)maximum flows/sec at the site and application level.

A sixth input may comprise monitoring data (telemetry) from existingactive sites or sites in monitor mode on media applications. Thetelemetry from each site for any media application present include thefollowing additional items: (a) jitter seen over time for audio and/orvideo including average and peak values, (b) packet loss seen over timefor audio and/or video including average and peak values and (c) an MOSScore over time for audio and/or video.

A seventh input may comprise site parameters such as: (a) a type ofsite, e.g., branch 152 or DC, (b) network types and number of suchconnectivity, (c) a list of applications or pointer to another site thatis similar, (d) a policy choice of pointer to another site that has theneeded policy and (e) a number of users 168 or pointer to another sitethat is similar.

In accordance with the exemplary embodiments described herein, what-ifuse cases and processing may be performed. When determining which pathsa specific application should take from a site, one may take thetopology of the network, apply the policy for the application, andreduce the topology to allowed connectivity based, at least in part, ona policy. The result is a set of network links that can carry theproposed application traffic.

When seeking to determine which paths traffic from a specific user 168and/or application take from a site, one may take the topology of thenetwork and apply the policy for the application and user 168 and reducethe topology to allowed connectivity based, at least in part, on apolicy. The result is a set of network links that can carry theapplication traffic for a specific user 168 or user group

When seeking to determine what a new branch 152 may look like in termsof device and network capacity, one may proceed as follows. First, themulti-tenant controller 122 may calculate normalized average and peakbandwidth utilization and maximum flows/sec at a site for everyapplication on a per site-size basis, categorized appropriately.Site-size may be decided by simultaneous flows at existing sites.

Then, the multi-tenant controller 122 may derive applications andpolicies at the new site from user input or by reference to anothersite. The multi-tenant controller 122 may derive simultaneous flows atthe new site by reference to another site or by taking the number ofusers 168 and multiplying by, for example, 20 with a floor value of 200.

The multi-tenant controller 122 may then build a sample “site model”that is a mix of estimated bandwidth (BW) utilization and estimatedmaximum flows/sec as follows:

-   -   Average-BW_(est)=Average of sum of every app's average BW scaled        to new site's size    -   Peak-BW_(est)=Peak of every app's peak BW scale to new site's        size Max-FLOW/SEC_(est)=Maximum flows/sec at site scale to new        site's size    -   Simul-FLOWS_(est)=Direct value as described above.

The resulting Simul-FLOWS_(est), and Max-FLOW/SEC_(est) may be used torecommend a device type and capacity while Average and Peak-BWest may beused to suggest network type changes to accommodate the average and peakbandwidth needs.

When seeking to determine how an application's traffic may change in anetwork due to a new proposed site, one may proceed as follows. First, amulti-tenant controller 122 may derive applications and policies at theproposed site from user input or by reference to another site. Next, onemay take the topology of the network and add the proposed site alongwith its network connectivity and types. Next, one may apply the policyfor the application and reduce the topology to allowed connectivitybased on policy. For every DC site, the multi-tenant controller 122 mayestimate the contribution of traffic (BW-INCR_(est)) from sites similarto the proposed site. Similarity may be estimated by site-size andpolicy similarity to account for the amount and type of applicationtraffic that comes in to the DC from the proposed site.

The result is a set of network links that can carry the traffic forevery application from and to the proposed site with a bandwidthincrease of BW-INCR_(est) at each DC site due to the addition of theproposed site.

In accordance with exemplary embodiments, data center 128 applicationsmay include an array of applications including, but not limited to,Exchange, SFDC and SAP. Such methods and systems as described herein maybe utilize and be utilized by all manner of data center applications.

In accordance with exemplary embodiments, such methods and systems forcontroller-based network topology identification may be applied toapplication sessions as described above. Further, such methods andsystems may be applied to various branch 152 types as described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   receiving information describing an addition of a first site        comprising at least one application to an existing network        wherein the information is selected from the group consisting of        type of site, planned connectivity to the site and planned        policies for the site; and    -   estimating an impact on the operation of the at least one        application and associated network traffic using statistical        analysis of monitored data collected from a second site similar        to the first site.

A method comprising:

-   -   receiving information describing a change to a policy for an        existing network wherein the information is selected from the        group consisting of the policy to be changed and the network        sites to which the policy is to apply; and    -   estimating an impact on the operation of the at least one        application and associated network traffic using statistical        analysis of monitored data collected from a second site similar        to the first site.

A method comprising:

-   -   receiving information describing a new network link to be added        to an existing network site wherein the information is selected        from the group consisting of the site and the network link to be        added; and    -   estimating an impact on the operation of the at least one        application and associated network traffic using statistical        analysis of monitored data collected from a second site similar        to the first site.

Any of the clauses above wherein the application analysis is performedon a per session basis.

Any of the clauses above wherein a branch type is selected from thegroup consisting of retail store bank, POS device, and distributedcomputing site.

Any of the clauses above wherein at least one application comprises adata center application.

Any of the clauses above wherein applications are selected from thegroup consisting of transactional applications and file transferapplications.

Any of the clauses above further comprising performing modeling andanalytics selected from the group consisting of Pareto and Weibull.

Any of the clauses above wherein a network type is selected from thegroup consisting of wired and wireless.

Any of the clauses above further utilizing parameters to categorize dataflows.

In traditional networking, SKUs are often used to account for productfeatures, scale and capacity. For example, a 100-node network might behandled by one SKU while a 1000 node network might need a “bigger” SKU.The availability of network may be provided by deployment of redundantunits. For example, a reliable network may have key points in thenetwork protected by two units of the same SKU so that if one shouldfail the other one takes over. This is referred to as “verticalscaling.”

In a web services architecture, every server 160 or a unit of systemcomponent is equally capable and can handle a certain number of load ortransactions. A load balancer, typically sitting in front of thesecomponents, distributes the load to the one or more instances of thesystem component, called a cluster. This model may provide bothredundancy and scale: A single instance failure means that instance isout of the cluster and the other instances take on the load. As the loadon the system increases, adding more instances may increase the capacityof the cluster. This is referred to as “horizontal scaling.”

There is a need for methods and systems enabling high networkavailability by running an assignment algorithm at a multi-tenantcontroller 122 in order to assign branch sites 152 (and associatedbranch devices 152) to at least two configurable devices 124 at eachdata center 128 within a network, with branch sites 152 mapped to hubpairs. At each data center 128 between the hub pair assigned to a branchdevice 152, a configurable branch device 152 may select one hub deviceas primary and one hub device as secondary. Traffic may bepreferentially sent to the primary hub device. Upon failure of theprimary hub device, the configurable branch device 152 may switch dataflows to the second of the devices in the hub device pairing and stoptraffic over the failed primary hub device. There may be several hubdevices in a given data center 128. This hub array in the data center128 may be horizontally-scaled and the mapping of a pair of hub devicesto a branch site 152 may be dynamically changed by a multi-tenantcontroller 122. This change may be fully automated depending ondynamically increasing or decreasing number of branch sites 152 and/orbased on the dynamic addition or reduction of capacity in terms of hubdevices in the data center 128.

According to the methods and systems of the present invention describedherein, a horizontal scaling solution may be used to reduce or eliminatethe network scaling problem. In embodiments, each device used at thedata center 128 (the “hub device) may handle a certain network trafficload coming from remote offices/branches. Hub devices may be clusteredtogether and the data load may be balanced/distributed across theelements of the cluster through the multi-tenant controller 122. In thisnetwork architecture a stateless hub device is enabled, and if one hubdevice fails, another hub device is able to take over without requiringany state exchange between the devices. Any hub device designated by thecontroller may be able to serve the traffic load needs of the remoteoffices/branches 152 network up to the hub device's load limits. Themulti-tenant controller 122 may compute and estimate the load fromdevices at each of a network's remote offices or branches 152 that sendtraffic to a hub device cluster. In embodiments, the multi-tenantcontroller 122 can assign hub devices to serve the load coming fromremote offices/branches 152, and dynamically add or delete hub devicesfrom the cluster. A network employing a multi-tenant controller 122, asdescribed herein, may include one or more of remote offices or branches152 that have one or two branch devices 152 each. The network may alsohave one or more data centers 128 that have one or more hub devices in acluster, and a multi-tenant controller 122 either in the data center 128or in the cloud that controls and orchestrates the network.

Referring to FIG. 11, when a new remote office is created and branchdevices 152 are added to the network by configuring them at themulti-tenant controller 122, the multi-tenant controller 122 may run an“assignment algorithm” and assign the remote office devices to twospecific hub devices at every data center 128. The algorithm mayconsider in its derivation of load and assignment if a remote officedevice was ever used in monitor mode. Monitor mode refers to a specialmode for a branch device 152 where the device is able to see all flowsmoving in and out of the branch 152 but doesn't alter anything on theflows. Data transfer statistics information collected from the branch152 may be used as an input to estimate traffic load. Internet linkbandwidth estimation conducted on each branch device 152 may be used asinput to estimate traffic load. The algorithm may further consider thecurrent known capacity limits of each hub device the current allocatedbranches 152 to each hub device in the cluster and the sum of theirestimated load on the hub device, the current allocated branches 152 toeach hub device in the cluster and the actual load on the hub device,the availability of total capacity of the hub cluster, the networkreachability of the new branch 152 to the all the elements of the hubcluster, or some other factor.

In embodiments, the branch devices 152 may establish Secure IPSec/VPNTunnels to each of its assigned hub devices at the data center 128. Abranch device 152 may choose one of the hub devices at the data center128 (of the two that were allocated to the device) as the primary. Ifthe Secure IPSec/VPN Tunnel to the primary hub device fails, the branchdevice 152 may switch its traffic destined towards the data center 128to the secondary hub device at that data center 128. In an embodiment,the branch device 152 may perform a seamless transfer from a primary hubdevice to a secondary hub device in the following manner: In theIPSec/VPN control plane communication, a branch device 152 may issue, asan example, a “START” command to the secondary hub device. The secondaryhub device may acknowledge the START command and update the localrouting information at the data center 128. On receiving theacknowledgement, the branch device 152 may start sending the traffic tothe secondary hub device on its IPSec/VPN tunnels. The branch device 152may stop sending traffic over the IPSec/VPN tunnels to the primary hubdevice and attempt to send a “STOP” command to the primary hub device.The primary hub device, if alive, may stop advertising routes at thedata center 128 for the branch 152 on one or more of the following i) onreceiving the “STOP” command, ii) after a certain time of non-receipt ofany traffic from a branch 152, and/or iii) if bidirectional forwardingdetection (BFD) detects loss of communication to the branch 152. If theprimary hub is not alive, routes advertised by the primary hub devicemay be automatically aged out at the data center 128.

Since a hub device's handling of traffic from a branch device 152 isdecided by the branch device 152 and its view of the IPSec/VPN Tunnelstates to the hub device, there is no need for hub devices to keep anystate and exchange states between them. As capacity needs on the hubcluster increase (e.g., due to more and more branches 152 comingonline), new hub devices may be introduced to the cluster and themulti-tenant controller 122 may start using them for the new branches152. If a hub device is permanently removed from the cluster (e.g., dueto permanent failure), the multi-tenant controller 122 may allocate anew or replacement hub device to the affected branch devices 152 thatwere previously using the failed hub device. If the load generated by abranch device 152 starts increasing and is no longer safely within theparameters originally used (e.g., in the “assignment algorithm”) forallocating the branch 152 to a specific pair of hub devices in thecluster, the multi-tenant controller 122 may re-allocate a new pair ofhub devices that can handle the revised load from the branch 152. Insuch re-assignments, the controller may i) allocate a new pair of hubdevices, ii) update the branch device 152 of a new secondary hub device(while keeping the current active hub device unchanged; hub devices maybe connected in a series), iii) force the branch device 152 to“failover” or “switchover” to the new secondary hub device that has morecapacity, and iv) update the branch device 152 of a new primary hubdevice. The result may be to successfully move the branch 152 from anolder pair of hub devices to new pair of hub devices that can handlehigher loads.

In accordance with exemplary and non-limiting embodiments, methods andsystems for hub high availability and network load and scaling mayutilize various hub device types and spoke devices as described hereinand may be enabled, at least in part, by one or more data center 128types as described herein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   receiving at a branch device an assigned first hub device and an        assigned second hub device associated with a data center;    -   establishing a VPN data tunnel to the assigned first and second        hub devices;    -   designating the first hub device as a primary device;    -   designating the second hub device as a secondary device; and    -   switching traffic destined for the primary device to the        secondary device based, at least in part, on a cost of a link.

A method comprising:

-   -   receiving at a branch device an assigned first hub device and an        assigned second hub device associated with a data center;    -   establishing a VPN data tunnel to the assigned first and second        hub devices;    -   designating the first hub device as a primary device;    -   designating the second hub device as a secondary device;    -   switching traffic destined for the primary device to the        secondary device if a failure of the VPN data tunnel to the        primary device is detected; and    -   switching traffic to the primary device and the secondary device        in a revertive mode and non-revertive mode.

A networked branch device configured to:

-   -   receive at a branch device an assigned first hub device and an        assigned second hub device associated with a data center;    -   establish a VPN data tunnel to the assigned first and second hub        devices;    -   designate the first hub device as a primary device;    -   designate the second hub device as a secondary device; and

-   switch traffic destined for the primary device to the secondary    device if a failure of the VPN data tunnel to the primary device is    detected.

Any of the clauses above further comprising switching traffic destinedfor the primary device to the secondary device based, at least in part,on a cost of a link.

Any of the clauses above wherein the first hub device and second hubdevice are assigned via an algorithm based, at least in part, on:

-   -   data transfer statistics information collected from the branch        device used as an input to estimate traffic load.    -   internet link bandwidth estimation performed at the branch        device used as input to estimate traffic load.    -   the current known capacity limits of each hub device.    -   the current allocated branch devices to each hub device in a        cluster and the sum of their estimated load on the hub device.    -   the current allocated branch devices to each hub device in a        cluster and the actual load on the hub device.    -   availability of total capacity of a hub cluster.    -   network reachability of the new branch device to the all the        elements of the hub cluster.    -   ability to use all branch circuits when communicating with hub        device.    -   ability to use lower cost circuits when communicating with hub        device.

Any of the clauses above wherein configurable devices comprise spokedevices.

Any of the clauses above wherein a data center type is selected from thegroup consisting of private cloud, scientific communities andco-location centers.

In traditional branch routing architectures, typically multiple branchrouters 162 are deployed in parallel to provide high availabilitytowards both LAN and WAN side. On the WAN side, private WAN links orinternet links are distributed on the multiple branch routers. On theLAN side, the switches 158 are connected to the multiple branch routers162 involving complex cabling schemes. On top of the complex cabling,various L2 (HSRP/VRRP) and L3 (OSPF/EIGRP) protocols are used to realizehigh availability with the parallel deployment. Further, complex trafficflows also happen where the packets first go to one of the routers, andthen get routed back on the LAN side to another router, which is bothinefficient and hard to troubleshoot when problems happen.

In accordance with various exemplary and non-limiting embodiments, thereis disclosed a branch routing architecture in which configurable devices124 are serially-placed in order to enable the bypass of data flowsaround a failed device to maintain access to all the available WANcircuits that terminate at a branch 152 of interest.

As illustrated with reference to FIG. 12, two or more devices 124 aredeployed in series. Both switches connect to a single configurabledevice 1202 which connects to a second configurable device 1204 inseries. Private WAN and internet circuits terminate on the secondconfigurable device 1204. As a result, cabling and L2/L3 topologiesremain the same and simple whether there are one configurable device 124or two. This allows the customers to switch between one (simpletopologies) or two configurable devices 124 (highly availabletopologies) with out making any change to the switch 158 or to the WANconnectivity, while at the same time being able to use the capacity onall the available WAN links. As illustrated, deploying two configurabledevices 1202, 1204 in series protects against a failure of a singleconfigurable device 124 at a branch 152 and provides high availability.

In accordance with various exemplary and non-limiting embodiments,configurable devices 124 deployed in series communicate with each otherusing a redundancy protocol to exchange state information comprising (1)who is active and who is in a standby mode of operation and (2)characteristics of various paths sent by active an active configurabledevice 124 to a standby configurable device 124 using a redundancyprotocol. This protocol is automatically employed by the configurabledevices 124 with out any action needed from the customers.

When an active configurable device fails, the standby configurabledevice may recognize the failure via one or more protocol keepalives andswitch to an active state. A keepalive (KA) is a message sent by onedevice to another device to check that the link between the two isoperating.

When the configurable device 124 fails or becomes inactive, theconfigurable device 124 automatically short circuits (called ‘bypass’)the interface connections such that the other (active) configurabledevice 124 has direct physical connection 148 to the circuits. Inaccordance with exemplary embodiments, when both devices are operatingin a healthy manner, they may self select which one will be active(based on an algorithm, e.g., lower serial number or controller giveninitial directive). If the self selected active device now has a failureand goes into bypass mode, then the backup device will become the newactive device as it will detect loss of heartbeat.

As a result, the current active configurable device may directly handlethe private WAN and Internet connections without any routing protocolsand other complexities. Further, in accordance with the state syncingdescribed above, the standby configurable device is already primed tobecome active and therefore is able to continue traffic forwardingfunctions within a short amount of time. Note that, unlike traditionalnetworks, the links are available to both configurable devices 124. Withthe hardware ‘bypass’ feature described above, the configurable device124 that became active after the failure of the other can direct accessto all the circuits.

In accordance with various exemplary embodiments, the described bypassfunctionality may be implemented in either software or hardware or acombination thereof.

In accordance with various exemplary embodiments, both the active andstandby configurable devices 124 may exhibit physical connectivity 148as described elsewhere herein. Further, such methods and systems asdescribed herein may be applied to various branch types as describedherein as well as various branch components 152 including, for example,switches and routers 162. The configurable devices 124 may furthercomprise spoke devices as described herein. The methods and systemsdescribed herein may further employ various switch types as describedherein.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   deploying in series a plurality of configurable devices        configured to communicate with one another via a protocol for        exchanging state information wherein at least one of the        plurality of configurable devices is in an active state and at        least one of the plurality of devices is in a standby state;    -   detecting, by the at least one of the plurality of configurable        devices in a standby state, a failure of a configurable device        in an active state via a protocol; and    -   switching the at least one configurable device in a standby        state to an active state.

A system comprising:

-   -   a plurality of configurable devices deployed in series and        configured to communicate with one another via a protocol for        exchanging state information wherein at least one of the        plurality of configurable devices is in an active state and at        least one of the plurality of devices is in a standby state;    -   wherein the at least one of the plurality of configurable        devices in a standby state is adapted to detect a failure of a        configurable device in an active state via a protocol and in        response thereto switch the at least one configurable device in        a standby state to an active state.

A method comprising:

-   -   deploying in series a plurality of configurable devices        configured to communicate with one another via a protocol for        exchanging state information wherein at least one of the        plurality of configurable devices is self-selected to be in an        active state and at least one of the plurality of devices is in        a standby state;    -   detecting, by the at least one of the plurality of configurable        devices in a standby state, a failure of a configurable device        in an active state via a protocol; and    -   switching the at least one configurable device in a standby        state to an active state.

Any of the clauses above wherein connectivity is physical

Any of the clauses above wherein branch components are selected from thegroup consisting of switches and routers.

Any of the clauses above wherein configurable devices comprise spokedevices.

Any of the clauses above wherein switch types are selected from thegroup consisting of managed switch, unmanaged switch and stackableswitch.

Internet Protocol Security (IPSEC) is a protocol suite for securingInternet Protocol (IP) communications by authenticating and encryptingeach IP packet of a communication session. Enterprise Site to Site IPSECVirtual Private Network (VPN) over Wide Area Networks (WAN) uses a suiteof encapsulation, data encryption and data authentication for data pathtunnels (e.g. encapsulating security payload (ESP) and AuthenticationHeader (AH)) and a separate control channel protocol such as, forexample, internet key exchange (IKE) and IKEv2 for the derivation of keyexchange and for decisions related to what traffic to encrypt betweenthe two gateways in each site.

Existing control methods typically bring in significant complexity forInformation Technology (IT) with regards to the management of and theconfiguration for key exchange. For example, for a set of N sites therecan be potentially on the order of N² IPSEC tunnels between the N numberof sites. In order to provide for the strongest levels of security, ITgenerally is required to manually configure rules for key generation ona per peer basis, which substantially increases configuration overhead.In instances where N is in the thousands, as when a networkedenvironment comprises thousands of nodes, this may become a prohibitivetask. As a result, IT typically will not deploy full mesh networks eventhough such is required to enable branch-to-branch communication.

For the strongest level of security, each gateway at each site has N−1tunnels to each peer site and is required to perform extremely CPUintensive and expensive key exchange computations so that both gatewayscan derive a common shared secret, which is then used to derivecryptographic session keys to secure the tunnel. In order to maintainperfect forward secrecy, this key exchange is typically repeatedperiodically for each tunnel resulting in thousands of key exchangeoperations. In several scenarios, multiple tunnels are needed betweenthe same pair of sites (e.g. VPN transport high availability, e.g.multiple WAN and Internet circuits, e.g. secure segmentation on the WANusing Virtual Wan (VxWAN)) 204.

In such instances, the number of key exchanges may be increased by afactor of 2 to 10 times. However, using software only methods, thenumber of such key exchange operations is limited and may not be able tomeet the required scale. The results often times in limited meshconfigurations wherein IT cannot build fully meshed networks withthousands to tens of thousands tunnels per site. Even the utilization ofexisting hardware based solutions may be unable to scale to the numberof tunnels that are needed for full mesh and for full meshes per VxWANbased WAN segment.

Existing methods such as GROUP VPN offer scalable implementations thataddress some of these concerns but compromise security as they use thesame session keys for communication between all devices across allencrypted data channels. In such instances, even a single compromise mayexpose the entire network.

In accordance with exemplary and non-limiting embodiments, there isprovided a method to replace traditional key exchange for InternetProtocol Security (IPSEC) data encryption by using a multi-tenantcontroller 122 to create multiple time-limited shared secrets, where themulti-tenant controller 122 generates the shared secrets for each IPSECencrypted channel and sends them over a bi-directional certificateauthenticated channel to the two IPSEC data channel end points. The endpoints then use the shared secret and nonces to derive session keys. Theshared secret and session key may be refreshed at an interval specifiedby a policy. The multiple shared secret mechanism ensures that even whenfaced with loss of communication with the multi-tenant controller 122the IPSEC end points can continue to refresh the time limited sharedsecrets and ensure perfect forward secrecy.

In accordance with exemplary and non-limiting embodiments, there isdisclosed a multi-tenant controller 122 driven key exchange model thatis a highly scalable and a granular Kerberos-like model for per pairscalable key generation and distribution over unsecure networks. Such amodel provides a zero configuration model for key exchange requiringlittle or no manual configuration by IT. In addition, there is provideda multi-tenant controller 122 generated separate shared secret pertunnel whereby granularity may be increased up to and including aseparate shared secret for each encrypted VXWAN segment. There isfurther provided the ability to horizontally scale in order to generatehundreds of millions of shared secrets needed for fully meshed branchnetworks. In addition, embodiments disclose a software only solutionthat does not require the use of custom hardware to achieve necessaryscale.

Further, there is provided a solution that utilizes several sources ofentropy for random number generation, which increases the strength ofthe shared secret key material generated by the multi-tenant controller122. Methods for random number generation may be selected and employedbased, at least in part, on available processing power. As describedmore fully below, such a solution utilizes a shared secret from themulti-tenant controller 122 along with random information from eachcommunicating element for a given data tunnel to generate session keysfor encryption and authentication of the data tunnel.

With regard to FIG. 13, there is illustrated a flowchart according to anexemplary and non-limiting embodiment. First, at step 1300, when themulti-tenant controller 122 makes a determination that a link should beestablished between two sites, the multi-tenant controller 122 generatesa common shared secret using following algorithm. First, themulti-tenant controller 122 generates X bits using, for example, aNational Institute of Standards and Technology (NIST) approvedcryptographically secure pseudo-random number generator (PRNG). Thevalue of X may vary depending on the type of NIST PRNG that is used. Therandom number generator may be seeded with a high level of entropy usingone or more of following mechanisms, (1) using operating system/dev/random, which relies on several entropy pools, (2) using FIPSapproved Intel RDRAND instructions and (3) by harvesting elementgenerated random numbers.

In accordance with various exemplary embodiments, continuous invocationsof the PRNG are used to derive multiples of X bits which areconcatenated to generate a shared secret from 512 to 8192 bits inlength.

Next, at step 1302, the multi-tenant controller 122 sends the sharedsecret to each of the elements, such as, for example, IPSEC data channelend points, over a transport layer 112 security (TLS) secured (with dataencryption and data authentication), bi-directional certificateauthenticated channel that it has with each channel end points.

Next, at step 1304, for each shared secret, the multi-tenant controller122 assigns a wall clock based start and end validity period. Themulti-tenant controller 122 generates multiple (N) shared secrets at thesame time and assigns to each of them consecutive wall lock validityperiods. The multi-tenant controller 122 sends these N shared secrets atthe same time to the channel end points.

Next, at step 1306, each channel end point may then generate 32-bytes of“nonce” comprising additional random data. The channel end points mayexchange these nonce values and may then use, for example, a RFC 5996specified key material generation method to generate four session keysper channel in order to (1) encrypt data to send to other element, (2)authenticate and attach a cryptographically secure message digest fordata send to other channel end points, (3) decrypt data received fromother channel end points and (4) validate that the message digestattached in the received data is correct.

In accordance with various embodiments, the channel end points encryptdata using ciphers that are specified by the multi-tenant controller122. At a regular interval determined by the multi-tenant controller 122the channel end points refresh the four session keys in a rekeyoperation using the given shared secret using the four steps describedabove.

Next, at step 1308, prior to expiration of the shared secret validityperiod, the channel end points may use the next shared secret (from theset of N shared secrets sent by the multi-tenant controller 122) andfollow the four steps described above to generate a new session key.Even if the multi-tenant controller 122 is not reachable for the entireduration of the N shared secrets validity period, the freshness of theshared secret is maintained. Once a single shared secret has expired,the channel end points continuously receive new shared secrets from themulti-tenant controller 122 and the multi-tenant controller 122 issuesup N total fresh secrets to the two channel end points.

In accordance with the preceding exemplary embodiments, perfect forwardsecrecy may be achieved by making the rekey interval the same as theshared secret validity period. Doing so helps to ensure that a freshshared-secret is used in each rekey. In various embodiments, storedshared secrets are sufficient to ensure network operation for a defaultperiod of time without refresh of new ones from the controller 122. Atypical default period of such a time is, for example, three days. Inexemplary embodiments, customers or users 168 of the network may set thedefault time period. In accordance with one exemplary embodiment,session keys may be rotated to configurable devices 124, such as channelend points, on an hourly basis using the same shared secret but newnonces for added security.

In accordance with an exemplary embodiment, the multi-tenant controller122 may operate as a certificate authority. When a configurable device124 is manufactured, it may connect to the multi-tenant controller 122for issuance of a manufacturing certificate. The configurable devices124 may use this certificate for a bidirectional authenticated TLSchannel for secure communication with the multi-tenant controller 122.When a configurable device 124 is shipped to a customer and the customermanually authorizes the configurable device 124, an additional claimcertificate may be installed by the multi-tenant controller 122 on theconfigurable device 124. Post authorization, the configurable device 124may use this certificate for bidirectionally authenticated TLS basedcommunication with the multi-tenant controller 122. The shared secretsmay be sent securely over this channel from the multi-tenant controller122 to the two channel end points.

In accordance with various embodiments, encryption algorithms may bechanged or updated at the multi-tenant controller 122 without impactingthe end points. In addition, the multi-tenant controller 122 may revokea device's certificate and tell other configurable devices 124 andentities not to trust it.

In accordance with various exemplary embodiments, the generation ofshared secrets need not be either entirely software or hardware based.Rather, a hybrid software/hardware process may perform the generation ofshared secrets.

The following are illustrative clauses demonstrating non-limitingembodiments of the inventions described herein:

A method comprising:

-   -   generating at a multi-tenant controller a common shared secret        for establishing a link between a first site and a second site;    -   transmitting the shared secret to each of the first site and the        second site over a secured channel;    -   assigning a wall clock based start and end validity period for        the shared secret;    -   sending the shared secret with a future validity to allow secure        link communication to continue if one or more elements in both        sites cannot communicate with the multi-tenant controller; and    -   using a separate shared secret per link per VXWAN

A method comprising:

-   -   receiving at a first channel end point a shared secret;    -   generating a plurality of nonce values;    -   exchanging the nonce values with a second channel end point;    -   generating a plurality of session keys; and    -   refreshing the plurality of session keys at a predetermined time        interval using the shared secret.

A system comprising:

-   -   a first site;    -   a second site in communication with the first site via a        network; and    -   a multi-tenant controller configured to generate a common shared        secret for establishing a link between the first site and the        second site and to transmit the shared secret to each of the        first site and the second site over a secured channel wherein        the multi-tenant controller is configured to assign a wall clock        based start and end validity period for the shared secret.

Any of the clauses above wherein shared secret generation is performedby software, hardware and/or a software and hardware hybrid.

In accordance with exemplary and non-limiting embodiments, there isprovided a method by which the WAN may adjust to yield to the needs ofapplications in order to provide an optimal or near optimal experienceto the users 168. Such optimization may be based at least in part on apolicy. A policy may be based at least in part on an applicationoperating on the network, such as a policy relating to the handling ofdata flows to ensure proper functioning of the application, the routingof application flows on the most suitable link present at a branchoffice 152, or some other criteria. Once an application flow is placedon an appropriate link, sufficient network resources may be guaranteedin accordance to a policy specification for the application flow.

A policy string 202 may allow a specific application or identity to bespecified that provides control over data flows occurring over thenetwork. Control may be per-application, per-identity, a combination ofapplication and identity, or based on some other parameter. In anembodiment, as part of a policy string 202, a virtual extensible WAN(VXWAN) 204 may be specified that causes a device to encapsulate aspecific set of flows identified by that policy in a unique VXWAN 204. AVXWAN 204 may comprise an identifier or label that may be put on thewire as data/packets belonging to the flows captured by the policy areforwarded between devices. A VXWAN 204 may comprise an optional uniqueencryption afforded only to packets belonging to the flows captured bythe policy. A VXWAN 204 may comprise a way to insert a VXWAN label at anentry point in the network and remove the label at the exit in thenetwork for the flow in a specific direction. A VXWAN 204 may bebidirectional in that the same VXWAN label can be used for bothdirections of the traffic. A VXWAN name space may be global andallocated and managed by a multi-tenant controller 122, as describedherein.

In an example, configurable spoke devices may perform traffic forwardingdecisions, and be provided information, including but not limited to:application identification details and/or application traffic profiles.Configurable devices 124, as described herein, may maintain pathcharacterization information. Path characterization may includeinformation on bandwidth availability on a link, latency profiles,traffic volume caps on a link and the like. The configurable device 124may then choose a link meeting all the constraints that is most optimalor most nearly optimal for an application at that time instant. Ratingof the links may be by the lowest network latency, or consideringapplication level transaction latencies, or some other criterion.

According to the methods and systems of the present invention describedherein, a multi-tenant controller 122 may maintain a network topology atleast in the form of a network topology database in which the entry andexit points for each device in a network are maintained. A multi-tenantcontroller 122 may also receive data from configurable devices 124indicating which domains are associated with an anchor domain, andassign these domains to a SaaS application 604 so that a fuller set ofentry points to the SaaS application 604 are known and stored by themulti-tenant controller 122. A configured device may collect monitoringdata, such as information relating to data flows that are associatedwith an application and/or domain that is associated with anapplication, such as an application in use at a network branch 152. Suchdata flow records may carry important information relating to the entryand exit points on a device. Millions of these data flow records may beexported from devices throughout the network to the multi-tenantcontroller 122. The multi-tenant controller 122 may store information,including, but not limited to, a network topology database that includesinformation on the entry and exit points of data flows occurring on eachnetwork device and how the data flows are interconnected, data flowrecords on a single data flow from multiple devices in the network, andanchor domains and other domains as described herein that are associatedwith the usage of an application on the network.

In embodiments, the multi-tenant controller 122 may use the storednetwork topology 508, domain and related data flow information toperiodically run an “asymmetric detection” algorithm 504 that in essenceidentifies the existence of a plurality of data flows that exited adevice through one path and return data flows that re-entered the deviceon a different path (i.e., asymmetry). Analytic techniques may also beused to characterize Layer 4 data flows that are associated withapplication usage. Configured spoke devices may collect and send to themulti-tenant controller 122 such Layer 4 level data flow. Data flowasymmetries that are associated with specific applications and/or anchordomains or other domains that are associated with an application may bedetected and corrected, as described herein. This correction may be madeon demand, and outside of the multi-tenant controller 122. The changemay be reported, for example by a spoke device, to the multi-tenantcontroller 122. The multi-tenant controller 122 may identify asymmetricflows associated with application usage on the network, and see whichdata center 128 devices participated in the transmission of the flow andreports this. The multi-tenant controller 122 may identify the IPaddress ranges on which this asymmetry is happening, aggregate them andreport them to a user 168 or administrator, so that the IP prefixconfiguration may be corrected on the sites. To prevent false positives,the algorithm may use additional weighting factors including otherdevices and different applications and their data flows, beforedeclaring existence of asymmetry in the network. The multi-tenantcontroller 122 may read data flow tables in order to allow themulti-tenant controller 122 to determine how the data traffic egresses(e.g., data deriving from an anchor domain or other domain). Theasymmetry may be detected, and the multi-tenant controller 122 may thennotify configured devices and the configured devices may take routingactions to ameliorate the data flow asymmetry for a given application'susage.

In accordance with exemplary and non-limiting embodiments, amulti-tenant controller 122 may be used to centrally view and controlthe network topology, configurable devices 124 in the topology and theapplication of policies to solve the operational needs of networkadministration. A multi-tenant controller 122 may record data indicativeof where all devices and applications are located, and identify and mapthe topology of a network and use the network view to determine optimalpolicy and device usage of network assets. The multi-tenant controller122 may, for example, monitor and record when a new site is added, thechanges to the network topology may then be updated. Because themulti-tenant controller 122 has access to the HTTP flow, themulti-tenant controller 122 may be queried to, for example, show allpaths between sites and simulate network function. The multi-tenantcontroller 122 may have access to bandwidth and links in its topologygraph of the network. Utilization of each link can also be gathered andstored for access by the multi-tenant controller 122. The multi-tenantcontroller 122 may simulate the effects of changes to a network. Themulti-tenant controller 122 may keep track of all configurations(devices, interfaces, capacities, policies and more) for all the devicesin the network. Configuration management may be in real or near-realtime to ensure minimal data latency. The multi-tenant controller 122 mayalso keep large amounts of monitoring data on traffic types, trafficload and application statistics, and may also allow for the creation of‘empty’ or hypothetical sites, specifically, ones that are not real butare, for example, being planned.

A multi-tenant controller 122 may be utilized to algorithmicallydetermine and establish a loop-free data-forwarding model that mayinclude the creation and management of forwarding tables 812. Thisalgorithm may account for network failures and adjust the loop-freedata-forwarding model to account for asset loss within the network. Amulti-tenant controller 122 may maintain a network topology at least inthe form of a network topology database in which the entry and exitpoints for each device in a network are maintained, and periodicallyrunning an algorithm using this network data to determine asymmetricdata flows and the devices associated with such asymmetric data flows.As described herein, a centrally configured multi-tenant controller 122may be both the creator and the source of (1) network segments andaddresses and (2) information indicative of how the network segments areconnected. The central multi-tenant controller 122 may then discoverwhat external network segments are not controlled by the routinginstance via a data center 128 or hub device and directly set upforwarding tables 812 on configured devices so that traffic is forwardedon to the correct interface, resulting in a loop-free forwarding modelwherein various rules are enforced.

In accordance with exemplary and non-limiting embodiments, a configureddevice may further collect monitoring data, such as information relatingto data flows transmitting through a device. Such data flow records maycarry important information relating to the entry and exit points on adevice. The multi-tenant controller 122 may store information,including, but not limited to, a network topology database that includesinformation on the entry and exit points of data flows occurring on eachnetwork device and how the data flows are interconnected, and data flowrecords on a single data flow from multiple devices in the network. Themulti-tenant controller 122 may identify asymmetric flows, includingasymmetric flows that are associated with an application or anchordomain, as described herein, and see which data center devicesparticipated in the transmission of the flow, and deduce that the flowis incorrectly going to, for example a hub device, and report this. Themulti-tenant controller 122 may identify the IP address ranges on whichthis asymmetry is happening, aggregate them and report to them to a user168 or administrator, so that the IP prefix configuration may becorrected on the sites.

According to the methods and systems of the present invention describedherein, a multi-tenant controller 122 may receive data from configurabledevices 124 indicating which domains are associated with an anchordomain, and assign these domains to a SaaS application 604 so that afuller set of entry points to the SaaS application 604 are known andstored by the multi-tenant controller 122. This may have advantages inmeasuring, monitoring and routing the true data flows associated with aSaaS application 604, whereas traditional techniques may underestimatethe traffic associated with a SaaS application 604 by not recognizingthe full set of domains that are actually generating traffic inassociation with an application. Domain types may include, but are notlimited to, top-level domains 608 (e.g., “.com”), geographic domains(e.g., country domains), and infrastructure domains (e.g., “.arpa”). Thedomains identified to be associated with the anchor domain may be sentto the multi-tenant controller 122, and at the multi-tenant controller122, further processing may be performed to eliminate the falsepositives and distill them to a corrected set of domains. A configurabledevice 124 within the network may detect an application's anchor domainand mark the source of the data and the time of detection. Followingthis time of detection, ongoing data flows from the same traffic sourcemay be marked as belonging to the application that is associated withthe anchor domain. The multi-tenant controller 122 may continue toreceive data regarding the traffic source from the configurable devices124 and classify the data flows.

In accordance with exemplary and non-limiting embodiments, anchor domainand other domain data may be analyzed using statistical and data miningtechniques, as described herein, for the characterization of applicationusage, by session, for performance and predictive planning purposes toimprove network performance. Data mining techniques like centrality andclassification may be applied to fine-tune models describing data flowsderiving from an anchor domain and/or the usage of an application. Theresulting models may be better able to predict the size and frequency oftransactions for a typical application session, as well as the frequencyof application sessions. The modeling and analytic methods used tocharacterize network activity associated with an anchor domain and/or anapplication session, and the corresponding network and bandwidthrequirements, may be used to monitor a network in real time forbandwidth requirements at the sub-channel level (transactional and bulkapplication types) and identify and predict trends in bandwidthrequirements. Based on anchor domain and application type detection,using real-time data flows, a multi-tenant controller 122 may analyzeapplication session data that it receives from configurable devices 124at the branch level to determine what amount of bandwidth is necessaryfor proper application performance. Application performance scores maybe used to record and adjust the bandwidth profile for an application,where the profile states performance and bandwidth criteria needed(i.e., a rule) for the type(s) of data flows detected during applicationsessions.

In embodiments, a shaper 154, as described herein, may be used to limitdata that is associated with, for example, a given anchor domain and/orapplication to a prescribed value. Shapers 154 may be added or deletedbased on the level of business priority associated with the traffic,such as traffic that is associated with anchor domain and/or applicationsession. This may be performed dynamically, for example, based onapplication demand, where the dynamic performance is carried out incompliance with a policy maintained at a multi-tenant controller 122.Performance-based routing may be accomplished by estimating linkcapacity automatically and dynamically, in real-time or near-real-time.Congestion control algorithms, as described herein, may be used forbandwidth estimation. For idle links the estimation may be performed ina manner that is similar to an Internet speed test. For active links,link capacity may be determined through continuous monitoring andcorrection. In an example, links may have an ingress and egress shaper154, as described herein, that controls how much traffic can be put onthe link or received from the link. Any traffic exceeding the shaper's154 limits may be dropped. A shaper's 154 limit may be set by bandwidthestimation logic.

In embodiments, network traffic may be classified based at least in parton a business priority, and bandwidth allocation to a plurality ofapplications running on a network may be determined based at least inpart on assigned business priorities. A network administrator may createmultiple business priority classes and assign each a priority orderand/or ranking A configured device may first detect the network type ofeach application data flow, for example, media, bulk or transactional,and create multiple queues for each business priority, for examplestrict priority 814, fair 818 and anomaly 820, as described herein. Ashaper 154 may be used in front of the anomaly queues to ensure that theanomaly flows do not impact bandwidth available for other flows.

A multi-tenant controller 122 may be used for automated prefix discoveryand propagation. A typical network may be made of many network segments,with each segment represented by a range of Internet Protocol (IP)addresses typically represented by a network address mask like so:10.10.10.0/24 where the “/24” is the mask. This range may representabout 254 IP addresses. When such network segments are presented by asummarizing router device 162, these ranges may be aggregated to ahigher “mask”—for example two segments 10.10.10.0/24 and 10.10.10.1/24can be aggregated to 10.10.10.0/23. Sometimes a router device 162 willdo this automatically but many times, these may be done manually byconfiguration. In embodiments, a multi-tenant controller 122 may gathernetwork segment information and thus be able to programmatically findthe most aggregated higher-level network address and mask. This processmay be called supernetting and may be instrumental to scale in onedisclosed non-limiting embodiment, and improve the automatic learningand control of the network.

For example, in case of data plane learning, once a flow arrives atconfigurable device 124, source IP information may be extracted from thepacket header and sent to the multi-tenant controller 122 along withinterface Virtual Local Area Network (VLAN) information on which thepacket was received by the device. Data packets, however, may not carrysubnet mask information. Therefore, a multi-tenant controller 122 maynot be able to immediately identify exact length of the prefix if itreceives information about a single or a handful of flows from clients512 on branch local segments. In this case, the multi-tenant controller122 may try to find the best-fit length of the prefix. For example: ifthe multi-tenant controller 122 receives information about two flowswith source IP addresses, let's say 192.168.1.1 and 192.168.1.2belonging to VLAN 10, it may generate a prefix 192.168.1.0/30 to startwith and advertise to other sites. Over time, if it receives informationabout another packet with source address of, 192.168.1.29, for example,on the same segment; it may refine the prefix length to be192.168.1.0/27.

Note that in data plane learning method, the configurable device 124 maychoose to aggregate the source IPs and partly perform what themulti-tenant controller 122 does, to aid the multi-controller 122 inconverging quickly.

The refinement process may continue until a multi-tenant controller 122determines the exact length of the prefix as it learns information aboutrest of the prefixes. Note that there may be no traffic loss during thelearning process. Also, if the local segment goes down and is detectedby the device, it may notify the multi-tenant controller 122 so thatroutes may be withdrawn from all the remote sites. The process of whatshould be the minimum length of the prefix or how frequently themulti-tenant controller 122 should generate the prefix and the like maybe user 168 configurable. Data plane learning may be referred to as slowlearning as the multi-tenant controller 122 may have to wait until ithas enough information to determine the exact prefix. Unlike data planelearning, device may learn the exact prefix length much faster if thereare routing devices behind the configurable device 124, whereby exactprefix information may be extracted from the control plane trafficbefore sending the info to the multi-tenant controller 122. Automatedlearning of the network prefixes without routing protocols and complexconfigurations for zero touch deployment of devices may be advantageous.Automatic removal of prefixes and withdrawal of routes with thoseprefixes when local segment is down may be advantageous.

Configurable devices may be used for the automated routing protocol-lessnetwork prefixes discovery. In traditional networks, routing protocolsmay be used to exchange routing information between devices. Localnetworks, however, may be required to be manually configured via networkstatements or redistribution for each routing protocol so that prefixescan be advertised to other routing peers. Configurable devices 124 inthe branch 152 may not run any routing protocols. Prefix discoveryinstead may be automated via data path learning at each branch site 152.Each branch device 152 may send the prefix information to a multi-tenantcontroller 122 which systematically may find the most aggregated higherlevel network address and mask via supernetting algorithm as mentionedin herein. A configurable device 124 may be configured to learn prefixinformation passively for the local network segments. A prefix may belearned via multiple ways such as Dynamic Host Configuration Protocol(DHCP), Address Resolution Protocol (ARP), snooping routing protocoltraffic, actual data plane traffic and the like.

In traditional networks, typically routing protocols are used toexchange reachable prefixes between routing peer devices. Source of thereachable prefixes is either through manual configuration via networkstatements or through redistribution from one routing protocol toanother.

For seamless deployment of configurable devices 124 in the data centers128, a multi-tenant controller 122 may learn about the local data centerprefixes automatically without requiring an administrator to manuallyconfiguring the prefixes and distribute those prefixes through out thenetwork for use in traffic forwarding.

In the data center 128, configurable hub devices may border gatewayprotocol (BGP) peer with the WAN-E router 178 and may learn all theprefixes including local data center prefixes as well as remote branchroutes learned via private WAN.

Configurable devices 124 may send all the prefixes learned from theprivate WAN to multi-tenant controller 122. A multi-tenant controller122 may run a local algorithm to identify and separate the localprefixes from the remote.

BGP-learned prefixes carry AS-PATH information, which is an ordered listof ASes and tell the receiving BGP peer about the ASes a given prefixhas traversed. The multi-tenant controller 122 knows the BGP AS numbersconfigured for a local configurable device 124 and the traditionalrouter 178 within the data center 128 that it is peered with. In oneembodiment, the multi-tenant controller 122 may identify the prefixesthat contain the only the AS numbers present in the data center 128, andmark those as prefixes as local to the data center 128. Multi-tenantcontroller 122 may employ other methods like BGP Autonomous System (AS)filtering to further refine the identified local prefixes in the datacenter.

Note that, if routes are withdrawn or any changes are made, a localdevice may detect these withdrawn routes via BGP updates and update themulti-tenant controller 122 accordingly. Multi-tenant controller 122 mayapply the algorithms on the updated information and adjust the localprefixes in the data center as necessary, allowing the network tocorrect and react to any changes automatically.

This may simplify the deployment of configurable device 124 in the datacenter and may save network administrators time to configure and removeprefixes any time any change is made within the data center 128.

The following examples in FIGS. 14 and 15 illustrate how prefix x(local) and prefix y (remote) may be learned with AS-PATH information.Note that even when there are multiple ASes within data center 128, theorder of AS numbers in the AS path list that hub device is peering with(AS 2 and AS 3 in the examples) may provide direction and mayappropriately identify whether the prefix is local or remote. Automatedlearning and withdrawal of the network prefixes for zero touchdeployment of devices in the data center 128 may be advantageous.

Multi-tenant controller 122-associated overlay networks may beintegrated with legacy systems. Using private MPLS 144 WAN, enterprisenetwork sites may be connected to the MPLS Service provider network in apoint to cloud type of model. Using the L3VPN service providerterminology, a customer edge (CE) router 180 may be connected to aprovider edge (PE) router 176. All the remote site routers 162 mayaccess the applications located in the data center 128 via the CE device180 in the data center 128. It may therefore be critical that there isno interruption to existing network especially the data center core 178and the CE (aka WAN-E or WAN Edge) device 180 in the data center 128 forseamless integration.

Referring to FIG. 16, a configurable device 124 may be deployed off pathin the data center 128 without interrupting the physically connectivityof the existing network as illustrated herein. A configurable device 124may be physically or logically connected to the CE device 180 in thedata center 128 via separate interfaces. A configurable device 124 mayBGP peer with Core 178 and CE 180 routers 162 and the like. Peering withCE 180 may be done in such a way that a configurable device 124 may onlyreceive the routes but may not send any routes to CE. This may ensure nodisruption to the existing operation of CE device. Peering with corerouters 178 may be done in such a way that, configurable hub device mayselectively advertise only those remote branch routes. Routeadvertisement to core routers 178 may be done by attaching a“no-advertise”, well-known community value. A well-known community valuemay instruct the core router 178 not to advertise configurablehub-injected routes to any other peers thereby requiring no specialfilters to prevent accidental advertisement of routes to any other peerswithin the network. This may ensure that a configurable device 124attracts only select traffic destined to branches 152. This may alsoensure that there is no impact on the traffic destined to non-controllerassociated sites improving the deployment and integration with anexisting network. Seamless integration without any sort of disruption toCE router 180 is advantageous. No disruption to non-controllerassociated sites is advantageous. Controlled traffic handling fornon-controller associated sites is advantageous. No filteringrequirements are advantageous.

A multi-tenant controller 122-associated environment may include zerotouch multicast. In the traditional network, enterprise customers maybuy multicast VPN service at a premium from MPLS providers so that theymay send multicast service between different sites in the network. Inaddition, a customer may have back up VPN via Internet 142. Typically,enterprises either choose not to send multicast traffic across PublicVPN due to performance issues and configuration complexity or deployproprietary solutions, investing in expensive equipment. However, suchcustomers are not able to use both the private and public VPN based onperformance criterion.

As illustrated in FIG. 17, configurable devices 124 may interceptmulticast traffic, specifically Internet Group Management Protocol(IGMP) traffic, passing through the branch device 152 whilesimultaneously forwarding the traffic to private WAN towards the nexthop routers 162, e.g. CE. A configurable device 124 in the branch 152may forward the IGMP report information to the multi-tenant controller122. A multi-tenant controller 122 may maintain a multicast groupdatabase based on the received IGMP protocol traffic, and may distributethe group member information to the configurable hub device located inthe data center 128. Upon receiving the multicast group member info fromthe multi-tenant controller 122, it may create a multicast state andplace the VPN links to the branches 152 that are members of the group. Ahub device may then reconstruct the IGMP join and send it to the corerouter 178, which may add the interface to the configurable hub in itsforwarding table 812. When a source located in the DC starts sendingpackets, a configurable hub device may receive a copy of the packet butreplicate the packet on the VPN links to the various remote branches 152that are members of the multicast group, as shown in FIG. 17.

Note that the source of multicast traffic may also be present at abranch 152, and in such cases, the multi-tenant controller 122 sends themulticast group information to the configurable device 124 present atthe branch 152, and this device performs the packet replication to thevarious member configurable device 124 over the VPN links. Theconfigurable device 124 may also choose to use the private WAN formulticast traffic if multicast is supported in the private WAN insteadof replicating traffic on the individual VPN links based on performance.

Zero configuration multicast traffic delivery may be advantageous.Performance based path selection for multicast traffic may beadvantageous.

A configurable hub device may provide a bridge/transit point betweenlegacy and hybrid WAN. In the traditional enterprise using privateIP/MPLS WAN, remote branches 152 and data centers 128 may be connectedto each other via a service provider MPLS 144 network. For redundancy,enterprise customers may choose two service providers and dual hometheir critical sites to two providers. In case of failure in one MPLSprovider, the sites may continue to reach each other via the 2^(nd)provider network. However, dual-homing all the sites may not be costeffective. Therefore, enterprises may choose to dual home only criticalsites and leave the other sites as single homed when possible. This,however, may create operational challenges for network administrator tomanage the routing and related policies to ensure traffic from singlehomed sites is allowed to transit through the appropriate dual homedsite(s) in steady state as well as upon failure conditions.

Routing policies related to making any given site a transit point in thetraditional networks may not be trivial and may require careful planningand complex configuration to avoid routing loops. For example, in FIG.18, Site 3 may be single homed and advertise a prefix which may bepropagated to all the sites connected to MPLS provider 1. Site 1 andSite 2 may be dual homed to both providers. Site 2 may advertise prefixto MPLS provider 2 and the prefix may arrive at Site 1. Site 1 may haveappropriate filters not to advertise prefix back to MPLS provider 1,which otherwise may create loops especially if the AS path informationwas lost due to route redistribution at any transit site. Similarly,Site 2 may not advertise the prefix if received from MPLS provider 2back to MPLS provider 1.

Additionally, appropriate configuration may need to be in place to allowthe traffic transit through site 2, when site 1 loses the connectivityto provider 1 when traffic from Site 3 is destined to Site 1.

A multi-tenant controller 122 based approach may provide seamlessintegration with the enterprise's existing network infrastructure.Enterprise customers may not need any complex configuration or routingpolicies to ensure proper traffic flow between sites during steady stateor failure conditions. Upon failure of MPLS WAN 144, a configurable hubmay be used as a transit point to seamlessly repair the part of a brokenWAN. Similarly, during the initial deployment phase, when not all of thesites may have been migrated to the multi-tenant controller 122associated environment, a configurable hub may provide a transit pointto facilitate seamless deployment in the rest of the network asillustrated in FIG. 19.

With the deployment model, configurable hub and branch devices 152 maybuild a secure and full-mesh overlay across a broadband Internetconnection 142. Configurable hub BGP may peer with core and wan-edgerouter 178 in the enterprise data center 128 and may receive the entirenetwork routes, including the routes from non-controller associatedsites. For example, as shown in FIG. 20, site 1 may reach site 2 onlyvia VPN due to losing connectivity to an MPLS provider 144. When site 1tries to send traffic to site 3, where the multi-tenant controller 122may not be deployed yet, traffic may be sent to a configurable hub atsite 2 first. Since a configurable hub has the knowledge of the entirenetwork, it may do an IP lookup and determine the site is not reachablevia the multi-tenant controller 122, hence it may forward the traffictowards a WAN-edge router 178, which then routes the traffic to theappropriate destination. A configurable hub may provide an easy point oftransition between VPN and a legacy network without requiring complexrouting policies. Seamless routing between VPN and legacy networkswithout explicit and complex routing may be advantageous. Highavailability for single homed sites upon failure may be advantageous.

A multi-tenant controller 122 may build an end-to-end topology mapcombining MPLS WAN 144 topology using various BGP attributes includingbut not limited to BGP community and provide a complete private WANtopology view to network administration via a Graphical User interface.

In a traditional network, a common choice of protocol between Enterpriseand MPLS Service provider, a.k.a PE-CE routing protocol, may be BGP.Enterprises typically may run a different BGP Autonomous System number(AS number) per site. As a result, when routes are exchanged from onesite to another via MPLS service provider network, an AS path attributecontaining all the ASes transited during the route propagation may becarried along with the prefix. In the central hub location, aconfigurable device 124 may peer with the enterprise WAN router 178 viaBGP and may receive the remote site routes with BGP path informationintact. A hub site may forward this information to a multi-tenantcontroller 122. The topology builder component of the multi-tenantcontroller 122 may leverage this information to identify local hub site(e.g. data center) routes and remote site routes and may build agraphical topological map. In addition, the multi-tenant controller 122may also have full knowledge of the VPN topology. Combining the two, thetopology builder may produce a complete end-to-end view of the entireenterprise WAN network.

The multi-tenant controller 122 associated approach may provide adynamic and complete view of the enterprise network combining all thepossible WAN in the network as well as ability to identify local vs.remote routes and the like. State transitions that may result from afailure in the MPLS WAN 144 and/or BGP route withdrawal on the privatenetwork may be reflected in real time.

Bidirectional forwarding may be used for the detection of private andpublic link failures. Using private MPLS WAN 144, enterprise networksites may be connected to the MPLS Service provider network in apoint-to-cloud type of model. Using the L3VPN service providerterminology, a customer edge (CE) router 180 may be connected to aprovider edge (PE) router 176. To meet customer Service Level Agreements(SLAs) for faster convergence upon failure, BFD may be used betweenPE-CE link along with a routing protocol. However, using BFD in thismanner may allow failure detection only for the local link or nodebetween a customer site and a provider edge router 176. Hence, a BFDsession may be configured at every PE-CE link in the enterprise network.Due to the fact that BFD may be running only on the local segment, itmay not be sufficient to detect end-to-end failures. An enterprisenetwork may not detect any soft or hard failures within a serviceprovider network, which could take hours and in some cases days totroubleshoot and pin point the root cause of the problem, possiblyincreasing the Mean Time To Repair (MTTR) and reducing the availabilityof the enterprise network. In addition, Provider Edge (PE) routerstypically may support only a limited number of BFD sessions and may notnecessarily be capable of supporting BFD on each and every PE-CE link.As a result, BFD may be available either only to high profile customersor may be offered as a premium service to the enterprise customers. Someenterprises may resort to establishing an overlay across the MPLSnetwork 144 and running BFD over the overlay network to detect brown outand other failures within the service provider network. This may addcomplexity and defeat the purpose of MPLS VPN 144 that may have beenmeant to outsource the WAN network while simplifying the networkoperation for enterprise network administrator.

BFD may be leveraged in a novel fashion to monitor the health of thepaths end-to-end between any two given sites without requiring complexconfiguration. As a result, the end-to-end traffic convergence uponfailures and especially in case of brownout may be very quick andincrease the overall availability and the user experience in theenterprise network.

In traditional networks, enterprise customers may desire to use BFDbetween PE-CE links along with BGP or one of the Interior GatewayProtocols (IGP) protocols including STATIC, Routing Information Protocol(RIP), Open Shortest Path First (OSPF) and Enhanced Interior GatewayRouting Protocol (EIGRP) and the like for fast failure detection.Failure detection by itself may be only a small part of the problem withan ultimate goal to recover the traffic as soon as possible. Therefore,to accelerate the route convergence and restore traffic on otheravailable paths, routing protocols such as BGP, OSPF and IntermediateSystem to Intermediate System (ISIS) and the like may register with BFDprocess. Upon link failure detection, routing protocols may beimmediately notified about such failures so that they can recalculatetheir routing table and find alternative paths to reach the desireddestinations. Since routing protocols are the consumers of the BFD, theexistence of routing protocols may be a pre-requisite for BFD to beeffective.

The multi-tenant controller 122 associated approach leverages BFD todetect end-to-end failures across private IP/MPLS WAN 144 in theenterprise network. Instead of the traditional process of registeringBFD with routing protocols, this approach may establish end-to-end BFDsession between configurable devices 124 at every enterprise site acrossprivate WAN. Each configurable device 124 may actively monitor thereachability to every other site via BFD without explicitly establishingend-to-end BGP or configuring any other routing protocol across privateWAN. Upon detecting anomalies along the path, a configurable device 124dynamically steers the traffic away from the affected path withoutmanual intervention. This may provide the ability to detect not onlylocal PE-CE local link of node failures quickly but also may enableenterprise customers to detect brown out and other failures in theservice provider network.

The multi-tenant controller 122 associated approach leverages BFD todetect end-to-end failures across private MPLS WAN 144 in the enterprisenetwork. Instead of the traditional process of registering BFD withrouting protocols, this approach may establish an end-to-end BFD sessionindependently between two given enterprise sites across MPLS WAN 144 andupon detecting failures, dynamically re-routes traffic without a need tonotify routing protocols to re-compute the alternative paths. Unliketraditional BFD, the effectiveness of this may not be limited to localPE-CE link/node failure but may be much broader in scope. It may enableenterprise customer networks to automatically detect brown out and otherfailures in the service provider network. Furthermore, this approach mayalleviate a need for the service provider to offer PE-CE level BFD thereby leveraging the valuable resources on the PE routers 176 for othercritical functions.

Hub high availability and switchover may be directed by multi-factorspoke devices. Each spoke site device may be assigned two hub elementsin each hub site for the purpose of HA to ensure that the spoke site maycontinue to have VPN tunnels to the hub site in the failure of a hubdevice. Using BGP or OSPF primary hub device may inject prefixesbelonging to the spoke into the core switch and specify the primary hubdevice as the preferred next hop for traffic in the hub site to spokesite direction. The determination of which of the hub devices to utilizemay be decided by the spoke site device. This invention describes howthe spoke site may decide which hub element is its primary hub.

A spoke element may use multiple factors to determine the preferred hubelement within the hub element pair that should be primary hub for thespoke site. The spoke may have multiple private and public WAN circuits.These circuits often have differing pricing models—the pricing isbandwidth based or volume based. Volume-based pricing may follow a cellphone plan like pricing model with some amount of allowed volume permonth for a fixed monthly cost and for volume exceeding the allowance acost per megabyte of consumption.

For each private and public WAN circuit, a spoke device may establish anInternet Protocol Security (IPSEC or IPSec) VPN Tunnel to both hubelements in the hub element HA pair assigned to it. The spoke device mayuse an algorithm to decide which hub element in the pair should be itsprimary. The algorithm may take as input the bandwidth per private andpublic WAN circuit, the pricing model per circuit, the health of theindividual IPSEC VPN tunnels to both the hub sites over each of thepublic and private WAN circuits, the routing reachability of the hubdevices to the hub core router 178 and the like. The goal of thealgorithm may be to optimize application performance while keepingvolume-based costs low. The algorithm may allow for a default HAbehavior and also may allow for an administrator to specify rules aboutwhich of the circuits in branch may be allowed to be default active,which ones are backup except on failure of default active circuits andwhen backup circuits may not be used. The algorithm may use the notionof protection groups to achieve its results. The spoke device 124 maydecide to pick one Hub Device 178 as its primary from the HA hub pairassigned to it as it is able to use a lower cost branch circuit. If theprimary hub device is now only reachable over higher cost volume basedcircuit but the spoke can reach the second device in the HA pair usingthe lower cost circuit then it may make the second hub device asprimary. Spoke driven HA decisions for hub site may be advantageous.Multi-factor determination of primary HA element based on applicationperformance, cost considerations and over-ride rules may beadvantageous.

Device authentication for device security may be provided prior to thecreation of secure tunnels, where such device authentication isenterprise-specific and/or specific to a configurable network utilizinga multi-tenant controller 122. Enterprise Site to Site IPSEC VPN overWAN networks may require that the two gateways or elements establishinga tunnel are mutually authenticated based on Enterprise requirements.The requirements may ensure that only trusted and authenticated devicesmay exchange private Enterprise data over private or public networksusing IPSEC VPN. Existing authentication methods may follow one of twoapproaches:

-   -   Use of manually configured pre-shared keys. This approach may        require IT to provision a separate pre-shared key per peer. For        1000 peers this may mean manually generating 1000 pre-shared        keys and configuring them 1 million times for a fully meshed        network. The alternate option is to use a single key, but the        compromise of even a single router 162 may expose the entire        network, leading to weaker security.    -   In lieu of pre-shared key customers may use PKI (Public Key        Infrastructure). This may require them to have a full PKI        infrastructure to manage certificates, keys and use the offline        CRL (Certificate Revocation List) distribution mechanism to        manage certificate revocation. They may have to ensure high        security and availability for their CA (Certificate Authority)        server(s). They may have to still manually provision each        gateway device to use PKI.

A VPN authentication disclosed non-limiting embodiment may use inbuiltPKI with tiered levels of certificate authentication which may eliminatenearly all manual configuration, may provide very high authenticationsecurity and may still give administrators control over authenticationof the elements. The disclosed non-limiting embodiment may provide forone or more of the following:

-   -   Three-tier, PKI-based authentication that may upgrade        authentication in stages for higher security.    -   First tier may be a Manufacturing Installed Certificate (MIC)        and private key that may provide for device authenticity when        shipped from authorized manufacturing sites.    -   Manual claim by a customer which may ensure IT is authorizing        each device before it is admitted in the network and may        participate in establishing VPNs and activating policy    -   Second tier may be a per-tenant Claim Installed Certificate        (CIC) which may bind the element to a Tenant following manual        authorization    -   Inbuilt and fully automated PKI infrastructure with separate        Certificate Authorities for MIC and CIC and which may manage        full lifecycle of the certificates    -   Customer-controlled device authorization revocation (declaim).    -   A customer may also control whether a given claimed device can        or cannot participate in VPN with other devices.    -   Integration with an existing customer PKI infrastructure by        allowing a customer to also install a Tenant Installed        Certificate (TIC), which may have been issued by customer's own        Certificate Authority.

At manufacturing time, prior to an element leaving a trustedmanufacturing site, the device may be installed with a signedcertificate and private key. The private key may be kept in a TPM(Trusted Platform Module) module and the like and the certificate may besigned by a proprietary manufacturing only Certificate Authority (termedas MIC CA). During manufacturing, the element may contact themulti-tenant controller 122 using a secure TLS encrypted channel and thelike to get its certificate signed. The multi-tenant controller 122 maycheck to ensure that the request is coming from a manufacturing locationand that the hardware ID/serial number is valid. The multi-tenantcontroller 122 may bind the hardware ID to a default tenant in thecertificate and may sign the certificate. An element that has beenmanufactured but not allocated to any tenant may be marked as“available”. The use of the TPM and signed certificate may ensure thatwhen tenant receives element it is a genuine element and can be trusted.The multi-tenant controller 122 may host the MIC CA, which may issuesigned certificates. The multi-tenant controller 122 may also maintainthe binding of the certificate to the specific hardware element. It alsomay maintain a revocation list of which hardware elements are no longertrusted and the like. Hardware elements that are reported to have beencompromised may be marked as revoked by the CA. The CA may use thisinformation to ensure that a tenant may claim only non-revoked trustedelements. When hardware is shipped to a tenant it may be marked“allocated” to that specific tenant. When an element, which only has aMIC and has been marked as “allocated” contacts the multi-tenantcontroller 122, the element may be allowed to be only “claimed” by atenant. The element may not be allowed to setup VPNs. The communicationbetween multi-tenant controller 122 and element may be TLS encrypted andPKI authenticated. The element to multi-tenant controller 122communication may use bi-directional certificate authentication, withthe element using the MIC as client certificate, and both parties mayvalidate that their certificates are signed by the proprietary CA.

When a tenant's administrator logs into the multi-tenant controller 122they may see all “available” elements allocated to them that arecurrently online. The administrator may validate that the elementhardware ID matches the one that they had ordered and that the elementmay be installed in the right customer location. They then manually“claim” the element. This provides multi-tenant controller 122 theauthorization from the administrator that this element may now fullyparticipate in the network and can establish VPNs.

The multi-tenant controller 122 may issue a new Claim InstalledCertificate to the element, an element ID separate from the hardware IDand it may bind the element to the tenant in the Claim InstalledCertificate (CIC) and sign the certificate. The multi-tenant controller122 may use a separate CIC CA for signing this certificate. Themulti-tenant controller 122 and element may then break the existingcommunication channel based on the MIC and the like and establish a newcommunication channel with the CIC. This may be a TLS encrypted andbi-directional certificate authenticated channel, with the element usingthe CIC as the client certificate, where both sides may validate thattheir certificates are signed by a trusted CA.

On validating that the element is in communication with a CICcertificate, the multi-tenant controller 122 may allow the element toestablish a VPN with elements at other sites in the customer network.Thus only a manually authorized element with a tenant specific claimcertificate may do VPN. This may represent the second PKI tier.

After an element has been claimed, if a tenant has their own PKIinfrastructure, then on an administrator's request the multi-tenantcontroller 122 may use signed certificates from the tenant's CA and itmay install them on the element. These signed certificates may be eithermanually provisioned by the administrator through their login or themulti-tenant controller 122 may use protocols such as SCEP (SimpleCertificate Enrollment Protocol) to acquire them. These certificates maybe called a “Tenant Installed Certificates” (TIC) and may be signed by aTIC CA and the like which is part of the tenant's own PKIinfrastructure.

After installation of TIC the element and multi-tenant controller 122again may break the existing communication channel established with theCIC communication and then re-establish it with the element again usingthe CIC or TIC as the client certificate. At this time they both may docertificate validation similar to the CIC-based communication asdescribed herein. In addition, the multi-tenant controller 122 validatesthat the element (if it connects with a CIC) may also have a signed TIC,which may have been signed by the tenant's TIC CA. This may representthe third PKI tier.

In addition to the MIC, CIC and TIC PKI based authentication andauthorization, the tenant administrator also may have controls totemporarily disable a particular claimed element from participating inVPN. This may not revoke the certificates but may only suspend theability of that element to do VPN. The administrator may enable asuspended element to re-establish VPN at time in the future.

If a MIC or CIC are near expiry or are damaged then the multi-tenantcontroller 122 may transparently allocate new signed certificates forthem without administrator intervention. For TIC certificates themulti-tenant controller 122 may transparently use SCEP or otherprotocols to get new signed certificates on behalf of the element.Customer may also manually install TIC certificates in lieu of oldexpiring or damaged ones.

When a customer no longer wants to use an element and wants to disposeit or return it for RMA (Return Merchandise Authorization) reasons, theymay “declaim” the element. When an administrator declaims an element themulti-tenant controller 122 may instruct the element to wipe its TIC andCIC and associated private keys. The multi-tenant controller 122 mayalso mark the element as being declaimed and no longer allocated to thecustomer. The multi-tenant controller 122 further may mark the CIC asrevoked and instruct the Tenant CA to mark the TIC as revoked. Theelement thus enters “available” state and may no longer be able toparticipate in establishing VPN, since it does not have CIC and is notin “claimed” state.

This three-tier authentication and authorization may provide in-depthsecurity and a PKI infrastructure for the first two tiers that may bemulti-tenant and may manage a full certificate lifecycle for the firsttwo tiers. The third tier may have the ability to integrate withexisting PKI infrastructure in a tenant's environment, acquire signedcertificates from a tenant's CA and use them for authorization for VPNestablishment. This may give administrators full control and ability tomanually authorize an element (claim the element) before it is admittedto the network and also de-authorize the element when they want todispose of it and the like. The conversion of this authorization to anew certificate/key may be bound to tenant or removed if the tenantbound certificate/private key is handled transparently. For a claimedelement further granular VPN level authorization may be also provided inan easy to use manner.

Site-to-site networking model and underlying VPN links/tunnels creationmay be based on dynamic rules. The multi-tenant controller 122 basednetworking model may use logical links that may then be realized usingIPSEC tunnels (also called as VPNLinks or vpnlinks) over public WAN(same as Internet 142) networks or private WAN (same as MPLS 144)networks for communication between sites. The multi-tenant controller122 may use a rules-based approach to dynamically bring up and tear downlinks between sites. The rules based approach may use one or more of thefollowing to decide when to bring up and tear down tunnels:

-   -   Knowledge of site type (hub or spoke)    -   Amount of data volume between spoke sites    -   Application performance between spoke sites    -   Tenant administrator given directives

When a Site is associated with a WAN Network, the multi-tenantcontroller 122 may create a logical “Site WAN Interface” and the like.

For every pair of Site-WAN Interfaces belonging to two separate sites(whether hub or spoke) the multi-tenant controller 122 may create a linkwhich may be a logical connection between the two sites. A link may beput into categories such as:

-   -   Hub to Spoke (H2S) links    -   Spoke to Spoke (S2S) links

[DYNAMIC RULE 1-DEFAULT] For every Hub to Spoke (H2S) link themulti-tenant controller 122 may instruct the right elements in both thesites to establish an IPSEC tunnel to activate the link. In the spoke,the right element may be the currently active element in a pair. In thehub the right element may be the designated primary hub element for thatspoke site.

[ADMINISTRATOR RULE 1] The multi-tenant controller 122 may providecontrol to the administrator to disallow a specific H2S link to beestablished. The multi-tenant controller 122 may use this directive andoverride the default rule.

[DYNAMIC RULE 2] The multi-tenant controller 122 may monitor totalvolume of traffic between each pair of spoke sites that is travellingeither over MPLS 144 between the sites or via a hub site which is actingas a transit site for traffic between the two spokes over IPSEC tunnels(i.e. traffic goes from Spoke 1 to Hub Site A over a IPSEC tunnel andfrom Hub Site A to Spoke 2 over a second IPSEC tunnel) and the like. Ifthe traffic volume exceeds a certain threshold over a certain timeperiod based on a formula, the multi-tenant controller 122 may decidethat the link between the spokes should be activated. It may instructthe elements in the two spoke sites to directly establish an IPSECtunnel between them so that the traffic between the spoke sites can usethe direct IPSEC tunnel between them.

[DYNAMIC RULE 3] For links activated using v. [DYNAMIC RULE 2], themulti-tenant controller 122 may continue to monitor total volume oftraffic between the two spoke sites. If the total volume over a certaintime period drops below a particular threshold then the multi-tenantcontroller 122 may decide to de-activate the link. It may instruct thetwo elements in the two sites to destroy the IPSEC tunnel.

[DYNAMIC RULE 4] The multi-tenant controller 122 may monitor applicationperformance between each pair of spoke sites for applications whose datais travelling either over MPLS 144 between the sites or via a hub sitewhich is acting as a transit site for traffic between the two spokesover IPSEC tunnels (i.e. traffic goes from Spoke 1 to Hub Site A over aIPSEC tunnel and from Hub Site A to Spoke 2 over a second IPSEC tunnel)and the like. If the application performance is poor, then based onhistorical latency and bandwidth information of IPSEC VPN directlybetween the two sites, or based on modeling and predictive analysis andthe like, the multi-tenant controller 122 may decide to activate thelink between the two spoke sites.

[ADMINISTRATOR RULE 2] The multi-tenant controller 122 may providecontrol to the tenant administrator to permanently allow a specificSpoke-to-Spoke link to be established. The multi-tenant controller 122may use this directive as an override to the rules.

[ADMINISTRATOR RULE 3] The multi-tenant controller 122 may providecontrol to the tenant administrator to disallow a specificSpoke-to-Spoke link to be established. The multi-tenant controller 122may use this directive as an override to the rules.

Traditional IPSEC VPNs may have one of following approaches:

-   -   A manually-configured spoke specified on each router 162 to        indicate which other routers 162 it should VPN with; or    -   Specify that the spoke router 162 may contact a hub router 162        for all traffic and if the hub router 162 may decide that if the        traffic is meant for another spoke site then it may tell the        originating spoke router 162 to establish an IPSEC VPN directly        with the destination spoke router 162.

The current disclosed non-limiting embodiment may provide one or more ofthe following new functionalities:

-   -   Provides a multi-tenant controller 122 driven central control        for the establishment of IPSEC across all configurable devices    -   Provides dynamic establishment of spoke to hub IPSEC tunnels as        the default with zero configuration    -   Provides an application performance driven IPSEC tunnel        establishment between sites    -   Provides a data volume driven IPSEC tunnel establishment between        sites    -   Provides for tenant administrator given directives approach to        permanently allow two sites to always communicate with each        using IPSEC tunnel over public WAN or private WAN    -   Provides for tenant administrator given directives approach to        permanently disallow two sites from communicating with each        using IPSEC tunnel over public WAN or private WAN

Existing centralized key generations (Kerberos and GROUP VPN and thelike) may require that the multi-tenant controller 122 be available atall times. These may operate within a highly reliable LAN or WANenvironment due to which the network reachability of the central keygenerator may be assured with a very high SLA. However for a centralizedmulti-tenant controller 122 that may be only reachable over Internetcircuits, it may be possible that due to multiple ISPs there may be adisruption in the multi-tenant controller 122 reachability. Theseoutages may happen due to natural disasters, breaking ofintercontinental submarine cables, equipment failure at core peeringpoints and the like. These disruptions may last from a period of fewhours to a few days and the like. In such a scenario the key generationmay not provide high availability and resiliency for the encryption datachannels.

According to the methods and systems of the present disclosure, VPN highavailability may be provided upon a failure to reach a multi-tenantcontroller 122. In the multi-tenant controller 122 driven model withcentralized generation of shared secrets by a multi-tenant controller122 for two sites to establish IPSEC tunnels, it may be possible thatdue to network connectivity issues explained earlier or a customerinternal network that the multi-tenant controller 122 may not bereachable for certain extended periods. Since shared secrets may expire,the multi-tenant controller 122 may generate new shared secrets ondemand by a set of elements, however if the elements cannot contact themulti-tenant controller 122 then they may not get new shared secretswhich will eventually cause the IPSEC tunnel to be brought down, therebydisrupting data path traffic.

This disclosed non-limiting embodiment provides a mechanism to allow thedata path to operate in a headless (devices actively functioning whileunable to communicate with the multi-tenant controller 122) mode forextended period of time. The multi-tenant controller 122 may allocate afixed validity period based on wall clock for a shared secret. For eachIPSEC data tunnel the multi-tenant controller 122 may issue multipleshared secrets with start and end validity periods in the future. Thenumber of shared secrets issued may cover the full headless period. Iftwo elements that have established an IPSEC tunnel cannot reach themulti-tenant controller 122, they still may have sufficient sharedsecrets to rekey the IPSEC data tunnel over the headless period.

Based on the security considerations and standardized best practices, amulti-tenant controller 122 may determine a maximum validity period forusing a specific shared secret. When the multi-tenant controller 122decides to activate a link using an IPSEC Data tunnel, the multi-tenantcontroller 122 may generate a shared secret for the two elements and setthe shared secret's start and end validity times based on wall clock.

The start time may be a time before the current wall clock time and theend time may be a time beyond current wall clock. The determination ofthe start time may be based on a specific distribution algorithm thattries to get a fair distribution of start times. The multi-tenantcontroller 122 may issue new shared secrets for millions of VPN linksand the fair distribution ensures that the multi-tenant controller 122may be evenly loaded and does not suffer peaks of re-issue load. Themulti-tenant controller 122 may have a default headless period value.The value may be changed by a tenant administrator within a multi-tenantcontroller 122 specified minimum and maximum bound and the like. Themulti-tenant controller 122 may use the headless period value and divideit by the maximum shared secret validity period to obtain the maximumnumber of shared secrets it should generate to cover headless expiryperiod. The multi-tenant controller 122 may send to both the elementsthe full list of pre-allocated shared secrets. The elements may use thefirst shared secret and when a certain period before it is to expire,the elements notify the multi-tenant controller 122 to request a newshared secret to ensure that they continue to have filled pipeline ofshared secrets covering headless period. The multi-tenant controller 122may respond to the first element that contacts it and issue a single newshared secret to both elements that have the IPSEC data tunnel. Themulti-tenant controller 122 may generate multiple shared secrets toensure that the total period from current time to maximum headlessperiod is fully covered with sufficient number of shared secrets. If theelement cannot reach the multi-tenant controller 122 to sendnotification, it may still continue to use the next available sharedsecret from the pre-allocated list. If the element's peer element cannotify the multi-tenant controller 122 then the multi-tenant controller122 may generate a new shared secret. If both elements cannot reachmulti-tenant controller 122 then the multi-tenant controller 122 may notissue a new shared secret.

If both elements cannot reach multi-tenant controller 122 and multipleshared secrets have expired and one or both of them are able to reachthe multi-tenant controller 122 after that, then the multi-tenantcontroller 122 may follow the same method and may issues multiple sharedsecrets to cover headless period from current time. If only one elementcan reach multi-tenant controller 122, it may continue to request newshared secrets from the multi-tenant controller 122. If one (or bothelements) cannot reach multi-tenant controller 122 and it has (or theyhave) consumed all shared secrets, it means that the element (or bothelements) may be operating beyond the allowed maximum headless period.In this condition the element may bring down the IPSEC tunnel. Theelement's peer if it is able to talk with the multi-tenant controller122 may continue to request new shared secrets from the multi-tenantcontroller 122 even though it is not able to use them. Thus the sharedsecrets refresh mechanism may operate as long as any one element canreach the multi-tenant controller 122.

This disclosed non-limiting embodiment may allow for the use of a Cloudbased multi-tenant controller 122 only reachable via Internet 142 thatissues centralized keys but still ensures that in cases of temporarydisruption that in reaching the multi-tenant controller 122 that thereis zero impact to existing encrypted data channels (IPSEC), whileensuring that the security of the encryption is preserved.

Centrally managed shim IP address may be used to optimize IPSEC securitypolicy. A spoke with multiple IPSEC VPN Tunnels over multiple public WANor private WAN interfaces may need to decide which egress VPN tunnel itshould use based on policy and the like. The spoke may maintain adatabase of currently active IPSEC VPN tunnel Security Associations (SA)and the like. A tunnel may consist of a pair of SAs one in inbound andanother in outbound direction. Each tunnel may be identified in thekernel using one or more of the following parameters—a 32-bit indexcalled as Security Parameter Index (SPI), and the destination IPv4 orIPv6 address of the IPSEC peer and the like. Each application flow maybe mapped to the pair IPSEC SAs and this mapping may be achieved in thekernel using a Security Policy Database (SPD). This database may consistof classification rules which may have fields based on header fields ofthe application flow. For each packet of an application flow the fieldsmay be extracted to form a key and a lookup done against theclassification rules in the SPD.

The number of entries in the SPD may become very large. As an examplefor a spoke with 1000 users each with two devices each having 20 to 30application flows may result in 40,000 to 60,000 entries in the SPD.This may slow down the SPD lookup and may add latency to packetprocessing.

Furthermore, each time there is a new application flow or when anexisting application flow dies, the SPD may have to be modified, andwhile it is being modified it may not be used for packet processingwhich may further delay packet processing. Addition or deletion ofapplication flows may be a frequent activity. This may be a problem evenfor smaller branches 152 with a few thousand SPD entries. The disclosednon-limiting embodiment may provide the use of an additional shim IPheader which may use a shim IP address per IPSEC tunnel. This shim IPheader may be attached to the application flow before the SPD lookup isdone. The use of the shim IP header may considerably reduce the numberof entries in the SPD. Since the shim IP are tied to the IPSEC tunneland the creation/deletion of tunnels may happen at a significantly lowerspeed compared to application flow creation/deletion the SPD may beupdated at a very low rate. Both these factors may improve packetprocessing performance.

Each IPSEC tunnel may be given a Path-ID which is a 64-bit number and,for each such Path-ID, the multi-tenant controller 122 may assign a pairof shim IP addresses for each side of the IPSEC tunnel.

The data path after doing a policy lookup may determine a Path-ID andthen may attach a shim IP header including the pair of shim IP addressesfor the Path-ID. The security policy data base may then be looked upusing only the Shim IP address. For a spoke with 1000 IPSEC tunnels thismay result in a SPD which has only 1000 entries compared to 40,000 to60,000 for a branch 152 with 1000 users. For smaller branches 152 with50 users and 2000 to 3000 flows the rate of change IPSEC tunnels may belower by factor X compared to the rate of change of application flows.This may result in a very low rate of update of the SPD compared to whatwill happen with SPD based on application flow header fields. Themulti-tenant controller 122 may use a database driven algorithm tomanage the IP address space. The algorithm may be highly scalable andmay manage the shim IPs for hundreds of millions of flows across tens ofthousands of tenants. The use of a shim IP header to improve SPD lookupperformance may be advantageous. The use of a multi-tenant controller122 driven highly scalable multi-tenant shim IP address management maybe advantageous.

Inline BFD may be used for IPSEC VPN tunnel health management andcontrol negotiation. Traditional IPSEC control protocol may use a methodcalled “Dead Peer Detection” (DPD) which may be a control channel methodof detecting if a peer is down. Since traditional IPSEC control channelmay be out of band, the control channel may be healthy but the datachannel may still be down. For example, the control channel may run onUDP port 500 which may be allowed by a firewall but the data channelIPSEC ESP may be blocked.

If dead peer detection detects that the control channel is down it maytear down the data channel and the peers may use IKE or IKEv2 and thelike to establish a new data channel. Thus control channel signaling maybe used to determine the health of a data channel. However, it may bepossible that the data channel is working well and the issue is onlycontrol channel related. This may cause unnecessary disruption in datachannel traffic. Instead of using DPD, the current disclosednon-limiting embodiment may use in-band signaling within the datachannel by sending Bidirectional Forwarding Detection (BFD) messagesbetween two ends of the IPSEC VPN tunnel. This may ensure that datatunnel failures are quickly detected. If BFD indicates a data tunnel isdown it then may trigger the control channel to begin negotiation todetermine the cause of failure. The control channel may not immediatelydestroy the IPSEC SAs but instead keeps them up until hard expiry. Thismay ensure that if the disruption in data tunnel is temporary the tunnelmay not be destroyed but may be used as soon as the disruption goesaway. The multi-tenant controller 122 associated approach may treat eachIPSEC data tunnel over public WAN or private WAN as a direct pathbetween two elements. BFD may be used to ensure that this path ishealthy and available. This may be similar to how routing would use BFDto detect health of a physical circuit that directly connects toadjacent routers 162 and the like.

The two sides use BFD as an application that may send BFD messages onboth sides using the Shim IP addresses as the source and destination IPaddresses. When the IPSEC VPN control daemon establishes an IPSEC datatunnel, it may signal the BFD daemon to create a BFD session. It mayprovide the source and destination IPs for the BFD packets and also thePath-ID for that session. The BFD daemon may send BFD packets per RFC5880. The BFD message interval may be kept as 750 ms. This may result ina 2.25 second failure detection period. If the BFD daemon detects thatthe tunnel is down, it may signal the IPSEC VPN control daemon andprovide it the Path-ID of the tunnel. The IPSEC control daemon may thenstart control channel negotiation with a relevant peer to find thereason for the failure and to take corrective action. The BFD daemon maycontinue to send echo packets and if it finds that the data tunnel is upthen it may again signals the VPN control daemon using the Path-ID toindicate that the IPSEC tunnel is up. The use of BFD as in bandsignaling to indicate health of IPSEC data tunnel may be advantageous.The use of data tunnel health failure to drive IPSEC control channelnegotiation instead of other way round may be advantageous.

According the method and systems of the present disclosure, VPN tunnelhealth management may be optimized for bandwidth. As explained hereinthe configurable device 124 may use BFD for monitoring the health ofIPSEC data tunnels. In order to support fast failover from an active toa backup IPSEC data tunnel and minimize traffic disruption, in onedisclosed non-limiting embodiment, the configurable device 124 may sendBFD echo packets as frequently as 750 ms. When there is a large numberof IPSEC tunnels (such as in thousands) from a branch 152 to other datacenter 128 and branches 124, the amount of BFD traffic can be large. Inorder to reduce the bandwidth consumption of BFD traffic but still doquick failure detection, this invention may use the encryptedapplication traffic received on a tunnel as an indication of the tunnelbeing up and suppress the BFD echo packets. In the absence ofapplication traffic, BFD packets may be used to check the health of thetunnel. In a variant of this approach, application traffic packets mayalso be used to carry the BFD signaling information.

NAT may be integrated for VPN tunnels and IP address change managementfor VPN tunnels with and without NAT. The devices in two sites that needto establish a VPN link may be behind a Network Address Translator(NAT). The NAT can be a destination IP NAT or a source NAT with PAT(Port Address Translation) type of NAT and the like. The NAT devicescould restart and, under reboot, they may also undergo an IP addresschange of their WAN facing interfaces. Only one side of the IPSEC tunnelmay be behind a NAT. The configurable devices 124 themselves may haveStatic IP addresses or DHCP IP addresses that may undergo change. TheNAT devices may be a Firewall NAT with rules which can move fromallowing IPSEC to disallowing IPSEC traffic and vice versa. If theydisallow traffic then they may keep a cached deny entry which needs totimeout, otherwise even if the policy is moved to allow, IPSEC sessionsmay still get denied due to a cached deny IPSEC entry.

The disclosed non-limiting embodiment described herein may ensure thatthe IPSEC data tunnel is kept up in most of the aforementioned scenariosand is required only as long as if there is a NAT device before one ofthe configurable devices 124. If there is a NAT device in front of bothconfigurable devices 124 then one of them should be a Destination NATdevice.

This disclosed non-limiting embodiment may use the notion of Initiatorand Responder and the use of multi-tenant controller 122 to tell eachside the IP address of the peer. If there is Destination NAT in front ofone of the parties then it may require the multi-tenant controller 122to specify the IP address of only that NAT as the peer destination IP.The disclosed non-limiting embodiment described herein may use NATTraversal. For example it may send IPSEC packets over UDP. Both partiesmay send request messages in which they may carry specific payloadsabout the original IP address and port number of the originating deviceand the IP address and port to which it may be sending the packet to.The receiving device may compare this information with the outermost NATTraversal UDP/IP header's IP and port. Using this each party finds outwhether it may be behind a static or dynamic NAT or whether the peer maybe behind a static or dynamic NAT and the like. Based on this they bothmay derive their role as initiator or responder. Once this role isestablished they may complete their control channel communication toestablish an IPSEC data tunnel. The two parties may also track dynamicchanges of IP addresses of either side and transparently update theirremote addresses while minimizing traffic disruption. If due to changeof IP or NAT role, NAT reboots, NAT policy changes and the like the datatunnel may come down then the control tunnel may try to re-establish thenotion of initiator and responder and may allow for the roles changingin order if necessary to keep the control channel up. If there isFirewall NAT device which denies the control channel communication dueto a cached denial entry whose timeout does not expire because ofcontinuous control channel negotiation packets then the control channelon configurable devices 124 may use an exponential back off timeoutmethod to decide when to transmit next control channel packet. Usingthis they may wait for few seconds to few minutes before sending nextcontrol channel packet. This may allow the firewall NAT to expire theircached denial entry. Updated policy on the firewall NAT may allow thecontrol channel communication and once the cached denial entry isdeleted due to expiry a new allow entry may be inserted by the FirewallNAT. Due to this control channel communication between configurabledevices 124 may eventually succeed. The ability to track change of IPAddress of the configurable devices 124 with and without NAT for site tosite IPSEC VPN may be advantageous. The ability to track change of IPaddress of source NAT devices may be advantageous. The ability to useexponential back-off times to send next control packet may beadvantageous.

Applications may be detected across tenants and across sites within asingle tenant. As described in the other embodiments above, the methodsand systems described herein may bring innovative approaches todetecting applications dynamically. The application identificationinformation that is dynamically learned from one or more sites may alsobe learned by the multi-tenant controller 122 and be pushed to othersites of the same tenant.

Further, since the multi-tenant controller 122 is delivered as acloud-delivered, multi-tenant service, the information learned at themulti-tenant controller 122 may be aggregated and sanitized, and thisaggregated information may be distributed to the sites of other tenantsas well. Both of the above may allow for the collective betterment ofthe application identification across sites and tenants. Without this,the information learned at one site may remain localized at the samesite, and every site may have to go through the learning processindependently. This collection and dissemination may allow for veryquick convergence of the application definition. For example, if adevice at site learned that sry1.lync-int.com is associated withoffice365, all the other sites come to know about this very quickly.

Spoke devices may detect applications, more specifically the SaaSapplications 604 using anchor domains based approach, described in theembodiments herein. In all the mentioned approaches, the applicationsdefinitions may get constantly refined as the traffic starts to flowthrough the spoke devices. These refinements are pushed to themulti-tenant controller 122, where they may be aggregated and sanitizedthrough analytics platform, and may be distributed to the other sites ofthe same tenant and those of other tenants. This is another example of aslow feedback loop that involves the devices and the multi-tenantcontroller 122.

Currently available solutions for WANs involve appliances and routers162 that may be either manually provisioned or provisioned through acentral mgmt. station which stops at just managing the devices and thelike. The disclosed non-limiting embodiment described herein providesfor a new multi-tenant controller 122 based approach towards learningand dissemination of application definitions toward the wide areanetworking space.

The multi-tenant controller 122 associated approach may in one disclosednon-limiting embodiment, involve all the HTTP domain names that thespoke devices were not able to associate with an application and mayidentify, analyze and categorize them to enhance the applicationdefinitions, in order, for example, to determine relevancy andirrelevancy.

Configurable devices 124 may inspect all the traffic going in and out ofa branch 152, and collect the set of HTTP domain names that tries toassociate them with the known applications dynamically, as stated in theabove embodiments. All the domain names that have not been found to berelated to a known application may be gathered and sent to themulti-tenant controller 122 for further analysis. At the multi-tenantcontroller 122, these domain names may be analyzed using data miningtechniques and the like, and they may get further categorized into oneor more of the following categories:

-   -   New applications, leading to new application definitions    -   Existing applications, resulting in the enhancement of existing        applications    -   Uninteresting, and therefore ignored.

This may help in improving the overall system's effectiveness inidentifying applications.

The disclosed non-limiting embodiment herein describes a WAN networkthat may constantly and automatically evolve and adapt based on thetraffic observed on a customer's network.

As described herein, a multi-tenant controller 122 allows for planningand visualizing changes to the network before the changes are actuallymade (i.e., the versioning). In such a “preview” mode, the networkadministrator is able to make proposed changes and see its effects indifferent ways. When such changes and the effects are deemedsatisfactory for the administrator user, he/she would want to commit thechanges to the network and thus converting the planned changes tocommitted changes. This may allow the “network” to be treated like adatabase—collection of assets, configurations, states and statistics.Databases are versioned, which allows tracking changes to the databaseas a sequence of commit transactions. Just like a Source Code Control &Versioning System that allows its various software components to beversioned and tracked through a series of commits and merges, which mayallow the ‘network’ to be versioned.

The administrator user ‘previews’ his changes and its effects based on aversion of the network, and once satisfied and she is ready to committhe changes, the multi-tenant controller 122 creates a new version ofthe network. More than one version of the network can be tracked andkept by the multi-tenant controller 122 so that if any change causesharm to the network, the administrator can go back to a previous ‘safe’version of the network.

The multi-tenant controller 122 may allow for two different versions tobe compared, which will highlight the configuration and asset inventorychanges. The multi-tenant controller 122 may keep all the configuration,assets inventory and state information, in addition to statisticscollected from the network. A version of the network is a snapshot ofconfiguration, assets inventory and state at the time of creation of theversion. For statistics, versioning is a version record added to thetime series of statistics data collected from the network. To comparetwo versions, the multi-tenant controller 122 does a ‘cliff’ of the twosnapshots representing the two versions. Statistics are not compared inthe same way. Instead, statistics may be analyzed in the context of theversions and their respective times of existence.

As mentioned in other embodiments, a multi-tenant controller 122 isdelivered from the cloud and administrative users get to interact withthe system at one central place, and may comprise a semi-distributedcontrol plane cache (with corresponding statistics). However thisdoesn't mean that all the elements deployed in a customer's network needto come to this single central place to retrieve their provisioning infoand perform their functions. Instead the multi-tenant controller 122functions are dis-aggregated and some of the latency-sensitive functionsare distributed across the globe to yield better response times to theelements. Elements in a customer's network may be deployed across widegeographies. These elements may need to fetch their provisioning infoand push the fine granular statistics to the multi-tenant controller122. If all of the multi-tenant controller 122 functions are centralizedlike the network portal and API gateway, the elements may suffer highlatencies in communicating with the multi-tenant controller 122 andeffectively performing their functions. To mitigate this, some of thekey latency sensitive multi-tenant controller 122 functions aredis-aggregated and distributed across the globe while the rest remaincentralized. All this happens in the backend, and the customer isunaware of all of this, and they continue to come to one place tointeract with the system. Distribution of these functions across widegeographies, while still functioning as a centralized multi-tenantcontroller 122 from customer's perspective may be advantageous.

Multi-stage, multi-factor classification and policy enforcement forperformance, path selection, SERVICE, and VXWAN selection may beprovided at the data path layer. The policy may use higher levelconstructs related to Application, Identity, Performance, Path, SERVICEand VXWAN based isolation. The information that is available in incomingflow packets, though, is at lower network layer 114. Incoming flows andpackets may need to be classified by the data path at both a networklayer and at a higher policy layer 112 to find which policy rule theymatch. This involves use of a two-stage classification.

Following this two-stage classification, the data path may need toselect the best path for the application based on VXWAN 204, SERVICE,Performance and Path directives in policy. The data path may use aspecific mechanism that ensures that policy is satisfied with the bestpossible performance 108 for the application and reachability 110 of theapplication.

A policy set may consist of policy rules. Each policy rule may specifyclassification columns including an Application and an Identity. Anapplication may be specified using higher-level L7 constructs andpotentially multiple L7 regular expression based rules. An applicationmay itself include a group of applications.

Similarly, identity may be specified using a string-based name. Eachidentity can specify an individual user 168 or device, or can specify agroup users 168 or devices and in some cases the groups may identityother groups. Each policy rule may also specify the action to take ifthe traffic matches the classification columns. The action is in termsof performance, path directive, SERVICE and VXWAN Isolation. There maybe multiple policy rules, which form part of a policy set. A policy setmay apply to multiple sites. A multi-tenant controller 122 sends all thepolicy rules of a policy set to the data path of the element in thesite.

In each policy rule a multi-tenant controller 122 may convert theapplication specification into an Application ID or List of ApplicationIDs and the identity specification into a list of Identity IDs. Themulti-tenant controller 122 may convert the path directives into a listof Path IDs, SERVICE into SERVICE ID, VXWAN 204 into network-isolationidentifier and Performance into a performance ID. It then may form thepolicy rule using these IDs and send the policy rule to the element datapath. It also provides an ID for each policy rule.

A data path may use multi stage classification method to classifytraffic. In the first stage it may take application traffic and identifytraffic as belonging to a specific application ID or a list ofapplication IDs and as belong to an identity ID or a list of identityIDs. As part of the first stage of classification a data path may use aset of helper modules that map the application and identity IDs tonetwork level constructs such as IP address, TCP and UDP ports, IP DSCP(Differentiated Services Code Point) fields, layer 2 VLAN Tag, layer 2VLAN priority, etc. In the second stage it may take the IDs coming outof the first stage and does another classification lookup to identifythe policy rule that the traffic matches. The data path may use aspecific algorithm for dis-ambiguity if multiple policy rules match theincoming traffic. It may use both the application and identity fields aswell as Path, SERVICE, VXWAN 204 and Performance fields fordis-ambiguity.

After finding a policy rule match, the data path may use the actionfields in the policy in order to enforce policy. For this, it may usehelper modules to map the path ID to data path level next hop interfacesor tunnels, to map the performance ID to data path level BW controlqueue and to map the network-isolation identifier to network path levelencapsulation shim. The data path may use a specific algorithm thatorders the path selection based on VXWAN directive, SERVICE directive,path directive rules and performance directive needs.

Once a final policy rule has matched, the data path may add a flow entryfor the incoming flow and subsequent packets belong to the flow use theflow entry rather using undergoing full multi-stage classification.

While an application and/or identity has been used at data path layer,for the purpose of security the use of both application and identity forpath selection for application performance and isolation at data pathlevel may be advantageous and the selection of the best path based on acombination of path directives, isolation needs and performance needsmay be advantageous.

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software, program codes,and/or instructions on a processor. The processor may be part of aserver 160, client 512, network infrastructure, mobile computingplatform, stationary computing platform, or other computing platform. Aprocessor may be any kind of computational or processing device capableof executing program instructions, codes, binary instructions and thelike. The processor may be or include a signal processor, digitalprocessor, embedded processor, microprocessor or any variant such as aco-processor (math co-processor, graphic co-processor, communicationco-processor and the like) and the like that may directly or indirectlyfacilitate execution of program code or program instructions storedthereon. In addition, the processor may enable execution of multipleprograms, threads, and codes. The threads may be executed simultaneouslyto enhance the performance of the processor and to facilitatesimultaneous operations of the application. By way of implementation,methods, program codes, program instructions and the like describedherein may be implemented in one or more thread. The thread may spawnother threads that may have assigned priorities associated with them;the processor may execute these threads based on priority or any otherorder based on instructions provided in the program code. The processormay include memory that stores methods, codes, instructions and programsas described herein and elsewhere. The processor may access a storagemedium through an interface that may store methods, codes, andinstructions as described herein and elsewhere. The storage mediumassociated with the processor for storing methods, programs, codes,program instructions or other type of instructions capable of beingexecuted by the computing or processing device may include but may notbe limited to one or more of a CD-ROM, DVD, memory, hard disk, flashdrive, RAM, ROM, cache and the like.

A processor may include one or more cores that may enhance speed andperformance of a multiprocessor. In embodiments, the process may be adual core processor, quad core processors, other chip-levelmultiprocessor and the like that combine two or more independent cores(called a die).

The methods and systems described herein may be deployed in part or inwhole through a machine that executes computer software on a server 160,client 512, firewall, gateway, hub, router 162, or other such computerand/or networking hardware. The software program may be associated witha server 160 that may include a file server, print server, domainserver, internet server, intranet server and other variants such assecondary server, host server, distributed server and the like. Theserver 160 may include one or more of memories, processors, computerreadable media, storage media, ports (physical and virtual),communication devices, and interfaces capable of accessing other servers160, clients 512, machines, and devices through a wired or a wirelessmedium, and the like. The methods, programs or codes as described hereinand elsewhere may be executed by the server 160. In addition, otherdevices required for execution of methods as described in thisapplication may be considered as a part of the infrastructure associatedwith the server 160.

The server 160 may provide an interface to other devices including,without limitation, clients 512, other servers 160, printers, databaseservers, print servers, file servers, communication servers, distributedservers and the like. Additionally, this coupling and/or connection mayfacilitate remote execution of program across the network. Thenetworking of some or all of these devices may facilitate parallelprocessing of a program or method at one or more location withoutdeviating from the scope of the invention. In addition, all the devicesattached to the server 160 through an interface may include at least onestorage medium capable of storing methods, programs, code and/orinstructions. A central repository may provide program instructions tobe executed on different devices. In this implementation, the remoterepository may act as a storage medium for program code, instructions,and programs.

The software program may be associated with a client 512 that mayinclude a file client, print client, domain client, internet client,intranet client and other variants such as secondary client, hostclient, distributed client and the like. The client 512 may include oneor more of memories, processors, computer readable media, storage media,ports (physical and virtual), communication devices, and interfacescapable of accessing other clients, servers 160, machines, and devicesthrough a wired or a wireless medium, and the like. The methods,programs or codes as described herein and elsewhere may be executed bythe client 512. In addition, other devices required for execution ofmethods as described in this application may be considered as a part ofthe infrastructure associated with the client 512.

The client 512 may provide an interface to other devices including,without limitation, servers 160, other clients 512, printers, databaseservers, print servers, file servers, communication servers, distributedservers and the like. Additionally, this coupling and/or connection mayfacilitate remote execution of program across the network. Thenetworking of some or all of these devices may facilitate parallelprocessing of a program or method at one or more location withoutdeviating from the scope of the invention. In addition, all the devicesattached to the client 512 through an interface may include at least onestorage medium capable of storing methods, programs, applications, codeand/or instructions. A central repository may provide programinstructions to be executed on different devices. In thisimplementation, the remote repository may act as a storage medium forprogram code, instructions, and programs.

The methods and systems described herein may be deployed in part or inwhole through network infrastructures. The network infrastructure mayinclude elements such as computing devices, servers 160, routers 162,hubs, firewalls, clients 512, personal computers, communication devices,routing devices and other active and passive devices, modules and/orcomponents as known in the art. The computing and/or non-computingdevice(s) associated with the network infrastructure may include, apartfrom other components, a storage medium such as flash memory, buffer,stack, RAM, ROM and the like. The processes, methods, program codes,instructions described herein and elsewhere may be executed by one ormore of the network infrastructural elements.

The methods, program codes, and instructions described herein andelsewhere may be implemented on a cellular network having multiplecells. The cellular network may either be frequency division multipleaccess (FDMA) network or code division multiple access (CDMA) network.The cellular network may include mobile devices, cell sites, basestations, repeaters, antennas, towers, and the like.

The methods, programs codes, and instructions described herein andelsewhere may be implemented on or through mobile devices. The mobiledevices may include navigation devices, cell phones, mobile phones,mobile personal digital assistants, laptops, palmtops, netbooks, pagers,electronic books readers, music players and the like. These devices mayinclude, apart from other components, a storage medium such as a flashmemory, buffer, RAM, ROM and one or more computing devices. Thecomputing devices associated with mobile devices may be enabled toexecute program codes, methods, and instructions stored thereon.Alternatively, the mobile devices may be configured to executeinstructions in collaboration with other devices. The mobile devices maycommunicate with base stations interfaced with servers 160 andconfigured to execute program codes. The mobile devices may communicateon a peer to peer network, mesh network, or other communicationsnetwork. The program code may be stored on the storage medium associatedwith the server 160 and executed by a computing device embedded withinthe server 160. The base station may include a computing device and astorage medium. The storage device may store program codes andinstructions executed by the computing devices associated with the basestation.

The computer software, program codes, and/or instructions may be storedand/or accessed on machine readable media that may include: computercomponents, devices, and recording media that retain digital data usedfor computing for some interval of time; semiconductor storage known asrandom access memory (RAM); mass storage typically for more permanentstorage, such as optical discs, forms of magnetic storage like harddisks, tapes, drums, cards and other types; processor registers, cachememory, volatile memory, non-volatile memory; optical storage such asCD, DVD; removable media such as flash memory (e.g. USB sticks or keys),floppy disks, magnetic tape, paper tape, punch cards, standalone RAMdisks, Zip drives, removable mass storage, off-line, and the like; othercomputer memory such as dynamic memory, static memory, read/writestorage, mutable storage, read only, random access, sequential access,location addressable, file addressable, content addressable, networkattached storage, storage area network, bar codes, magnetic ink, and thelike.

The methods and systems described herein may transform physical and/oror intangible items from one state to another. The methods and systemsdescribed herein may also transform data representing physical and/orintangible items from one state to another.

The elements described and depicted herein, including in flow charts andblock diagrams throughout the figures, imply logical boundaries betweenthe elements. However, according to software or hardware engineeringpractices, the depicted elements and the functions thereof may beimplemented on machines through computer executable media having aprocessor capable of executing program instructions stored thereon as amonolithic software structure, as standalone software modules, or asmodules that employ external routines, code, services, and so forth, orany combination of these, and all such implementations may be within thescope of the present disclosure. Examples of such machines may include,but may not be limited to, personal digital assistants, laptops,personal computers, mobile phones, other handheld computing devices,medical equipment, wired or wireless communication devices, transducers,chips, calculators, satellites, tablet PCs, electronic books, gadgets,electronic devices, devices having artificial intelligence, computingdevices, networking equipments, servers 160, routers 162 and the like.Furthermore, the elements depicted in the flow chart and block diagramsor any other logical component may be implemented on a machine capableof executing program instructions. Thus, while the foregoing drawingsand descriptions set forth functional aspects of the disclosed systems,no particular arrangement of software for implementing these functionalaspects should be inferred from these descriptions unless explicitlystated or otherwise clear from the context. Similarly, it will beappreciated that the various steps identified and described above may bevaried, and that the order of steps may be adapted to particularapplications of the techniques disclosed herein. All such variations andmodifications are intended to fall within the scope of this disclosure.As such, the depiction and/or description of an order for various stepsshould not be understood to require a particular order of execution forthose steps, unless required by a particular application, or explicitlystated or otherwise clear from the context.

The methods and/or processes described above, and steps thereof, may berealized in hardware, software or any combination of hardware andsoftware suitable for a particular application. The hardware may includea dedicated computing device or specific computing device or particularaspect or component of a specific computing device. The processes may berealized in one or more microprocessors, microcontrollers, embeddedmicrocontrollers, programmable digital signal processors or otherprogrammable device, along with internal and/or external memory. Theprocesses may also, or instead, be embodied in an application specificintegrated circuit, a programmable gate array, programmable array logic,or any other device or combination of devices that may be configured toprocess electronic signals. It will further be appreciated that one ormore of the processes may be realized as a computer executable codecapable of being executed on a machine readable medium.

The computer executable code may be created using a structuredprogramming language such as C, an object oriented programming languagesuch as C++, or any other high-level or low-level programming language(including assembly languages, hardware description languages, anddatabase programming languages and technologies) that may be stored,compiled or interpreted to run on one of the above devices, as well asheterogeneous combinations of processors, processor architectures, orcombinations of different hardware and software, or any other machinecapable of executing program instructions.

Thus, in one aspect, each method described above and combinationsthereof may be embodied in computer executable code that, when executingon one or more computing devices, performs the steps thereof. In anotheraspect, the methods may be embodied in systems that perform the stepsthereof, and may be distributed across devices in a number of ways, orall of the functionality may be integrated into a dedicated, standalonedevice or other hardware. In another aspect, the means for performingthe steps associated with the processes described above may include anyof the hardware and/or software described above. All such permutationsand combinations are intended to fall within the scope of the presentdisclosure.

While the invention has been disclosed in connection with the preferredembodiments shown and described in detail, various modifications andimprovements thereon will become readily apparent to those skilled inthe art. Accordingly, the spirit and scope of the present invention isnot to be limited by the foregoing examples, but is to be understood inthe broadest sense allowable by law.

We claim:
 1. A method comprising: receiving, by a multi-tenantcontroller, information describing an addition of a first sitecomprising at least one application to an existing network, wherein thereceived information includes an application profile corresponding tothe at least one application, a type of the first site, a plannedconnectivity to the first site, a number of users of the first site, andplanned policies for the first site; and estimating an impact on theoperation of the at least one application and associated network trafficusing statistical analysis of monitored data collected from a secondsite similar to the first site, wherein the statistical analysis takesinto account at least one of: an average bandwidth of the at least oneapplication on the second site scaled to a size of the first site, apeak bandwidth of the at least one application on the second site scaledto the size of the first site, a maximum flow per unit time of the atleast one application on the second site scaled to the size of the firstsite; and an estimation of simultaneous flows at the first site usingcorresponding simultaneous flows from the second site.
 2. The method ofclaim 1, further comprising performing application analysis on a persession basis.
 3. The method of claim 1, wherein a type of site isselected from the group including a retail store bank, a POS device, anda distributed computing site.
 4. The method of claim 1, wherein the atleast one application comprises a data center application.
 5. The methodof claim 1, wherein the at least one application is selected from thegroup including transactional applications and file transferapplications.
 6. The method of claim 1, further comprising performingmodeling and analytics selected from the group including a Paretoanalysis and a Weibull analysis.
 7. The method of claim 1, wherein anetwork type is selected from the group including wired and wireless. 8.The method of claim 1, further utilizing parameters to categorizenetwork traffic.
 9. A method comprising: receiving informationdescribing a change to a policy for an existing network that includes aplurality of network sites, wherein the received information includesidentification of the policy to be changed and the network sites towhich the policy is to apply; and estimating an impact on the operationof the at least one application and associated network traffic usingstatistical analysis of monitored data collected from a second site ofthe plurality of network sites similar to the first site, wherein thestatistical analysis takes into account at least one of: an averagebandwidth of the at least one application on the second site scaled to asize of the first site, a peak bandwidth of the at least one applicationon the second site scaled to the size of the first site, a maximum flowper unit time of the at least one application on the second site scaledto the size of the first site; and an estimation of simultaneous flowsat the first site using corresponding simultaneous flows from the secondsite.
 10. The method of claim 9, further comprising performingapplication analysis on a per session basis.
 11. The method of claim 9,wherein a type of site is selected from the group including a retailstore bank, a POS device, and a distributed computing site.
 12. Themethod of claim 9, wherein the at least one application comprises a datacenter application.
 13. The method of claim 9, wherein the at least oneapplication is selected from the group including transactionalapplications and file transfer applications.
 14. The method of claim 9,further comprising performing modeling and analytics selected from thegroup including a Pareto analysis and a Weibull analysis.
 15. The methodof claim 9, wherein a network type is selected from the group includingwired and wireless.
 16. The method of claim 9, further utilizingparameters to categorize network traffic.
 17. A method comprising:receiving, by a multi-tenant controller, information describing a newnetwork link to be added to an existing network first site having atleast one application, wherein the information comprises identificationof the existing first site, a number of users of the at least oneapplication, and identification of the network link to be added; andestimating an impact on the operation of the at least one applicationand associated network traffic using statistical analysis of monitoreddata collected from a second site similar to the first site, wherein thestatistical analysis takes into account at least one of: an averagebandwidth of the at least one application on the second site scaled to asize of the first site, a peak bandwidth of the at least one applicationon the second site scaled to the size of the first site, a maximum flowper unit time of the at least one application on the second site scaledto the size of the first site; and an estimation of simultaneous flowsat the first site using corresponding simultaneous flows from the secondsite.
 18. The method of claim 17, further comprising performingapplication analysis on a per session basis.
 19. The method of claim 17,wherein a type of site is selected from the group consisting of retailstore bank, POS device, and distributed computing site.
 20. The methodof claim 17, wherein at least one application comprises a data centerapplication.